Austin(CNN) The capital of Texas is a pretty liberal town. Proudly so.
Crosswalks repainted in rainbow Pride colors. Signs welcoming gay patrons. It has a vibe that even some locals boast is more like Berkeley, California, than a stereotypical southern city.
And yet residents who live in this progressive neighborhood are represented in the US House by a Republican congressman, thanks to gerrymandering after the 2010 census intended to dilute the power of the Democratic vote here -- a practice known as cracking.
Now, after the 2020 census, Texas Republicans who drew the new map are taking a different approach, moving Democratic voters into areas where they will be represented by Democratic lawmakers and doing the same for Republicans -- a gerrymandering tool known as packing.
"Here in Austin, what the Republicans did was pack as many Democrats into as few districts as possible in order to shore up as many other Republican districts as they could to cement their majority in the Texas congressional delegation for years to come," Texas state House Democratic Caucus Chair Chris Turner said while walking down an Austin street.
Regardless of the approach, gerrymandering is all about elected officials trying to keep their power by manipulating the makeup of the population that they represent, thereby making it easier for their party to win. The consequences are severe. Lawmakers in both parties speaking candidly admit that gerrymandering House districts is one of the big reasons that the chamber has become more partisan over the last several decades.
More on the ramifications of gerrymandering in a bit. But first, a primer.
The Constitution says that House seats should be equally apportioned among states. Given today's population, that's about 750,000 people per representative. To make that happen, states redraw congressional districts every 10 years after each census to reflect changes in population. And though this is, in theory, a straightforward process, it is all politics.
"Redistricting is simply the process of redrawing the lines. Gerrymandering is redrawing the lines with the intent to benefit a particular party or group or individual," said American University professor David Lublin.
Now, more on those two main types of gerrymandering: packing and cracking.
Cracking, when politicians divide up voters from the opposing political party in an effort to dilute their influence, often happens around urban centers, which tend to lean Democratic. It's how Austin was gerrymandered under the previous map. Pieces of the city -- including that liberal block we walked on -- were spread out among several surrounding districts and their voting influence, mostly Democratic, was outweighed by Republicans.
Packing, on the other hand, occurs when politically similar groups are jammed together in fewer districts, providing a single party more guaranteed wins. It's how politicians gerrymandered Austin under the new map last year. Instead of sprinkling Democratic voters throughout red districts, most of downtown Austin is now part of a new, assuredly Democratic district. The surrounding Republican districts also got safer, because they no longer contain those Austin Democrats.
Texas Republican Will Hurd is a moderate who left Congress last year frustrated over the lack of bipartisanship.
"It's incumbent protection," he said flatly during an interview at his San Antonio home, speaking about gerrymandering.
"The red seats got redder and blue seats got bluer," Hurd said of the state's new map, which the GOP-controlled legislature passed and the Republican governor signed in October.
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He argued that one consequence of such gerrymandering is that districts across the country are becoming politically homogeneous -- be it Republican or Democrat -- and, in turn, it's much easier for incumbents to win reelection.
"You shouldn't think that, hey, once you're in, you should be able to stay in. Because that makes you soft. That makes you stop thinking about solving problems for your bosses, which are the 750- to 800,000 people that you ultimately represent."
"When you have a lot of redistricting manipulation, it feels more and more like the representatives are choosing their constituents, rather than vice versa," Lublin said.
Hurd represented a district in southwest Texas that Hillary Clinton won in 2016. Because of the competitive nature of his seat, he said, his approach to governing was pragmatic and bipartisan.
"My job was real simple: figure out a problem, and then go and tell people I was going to solve it," Hurd said. "My title was representative. That means I represent everybody -- people that voted for me, people that didn't vote for me, and the people that didn't vote at all," he added.
In 2020, when Hurd did not seek reelection, Texas' 23 District voted for then-President Donald Trump and for the Republican congressional candidate, now-Rep. Tony Gonzales.
Congressional crossover districts like Hurd's used to be -- where voters choose a president and a representative from different parties -- are virtually disappearing.
According to the Cook Political Report, in 1996, 108 of the 435 congressional districts were crossovers. By 2016, that number had shrunk to 36. Today, there are just 16. That means that less than 4% of members of the House come from districts where there is any significant pressure from voters on the other side of the aisle.
Democratic Rep. Sheila Jackson Lee has represented the Houston area in Congress for nearly 30 years. She said the first legislation she worked on when she came to Washington was bipartisan. "We didn't know any better. We thought we had to work together."
Now, she said, there are fewer members of Congress who have experienced "moments when we have to work together, even though we have different opinions."
"How long can people enjoy having difficulty in getting good work done?" she asked.
"I think we have an obligation that we should not let redistricting change America," Jackson Lee said, adding, "I think it has."
Texas state Rep. Jacey Jetton, a Republican, was on the redistricting committee that rewrote the maps after the 2020 census for the Texas legislature and the US House.
With the new map, his state district is becoming more safely Republican.
He argued it was drawn so that "communities of interest" are put together, and pushed back on the notion that it is about incumbent protection.
"Even if it's a Republican district, they still go through a Republican primary," he said.
"And so the incumbent is not necessarily safe just because their district is still reflective of their party affiliation," Jetton told us during an interview in his Austin statehouse office.
He is right, and therein lies a key reason for increasing polarization.
When the results of a general election are a foregone conclusion, the primary race is what matters. A threat from inside the party -- be it Republican or Democrat -- can pull candidates to the extreme edges of their party.
"There is no scenario in which a Republican could win my House district," said Turner, the Democratic state representative whose district will be even more firmly blue under the new legislative map.
"The only way I would lose reelection is if I had an opponent (in) the Democratic primary who managed to beat me," he said, quickly adding that he doesn't currently have one.
But if he did, he said there is "no question" a primary opponent would pull him to the left.
Partisan districts sending partisan representatives to the US House is a major reason for Washington gridlock in recent years.
"No one's going to challenge you for being too extreme in your party primary, but some may challenge you as a sellout if you made the compromises that are an inherent part of governing under our system," said Lublin.
As candidates become more firmly entrenched at the edges of their party, they have even less incentive to work across the aisle.
Republican Rep. Pete Sessions' current 17th District includes what he says are about 80,000 people who live in Austin and tend to be more liberal. The district was part of the old gerrymandering model aimed at diluting Democratic votes. Now, with the new approach of packing Democrats and Republicans in separate districts, he will no longer represent those Austin voters.
"We've by and large entered a period of time where Republicans want to be represented by Republicans and Democrats want to be represented by Democrats," Sessions said.
"It makes things to where the person that represents those districts more hardened in their belief," he admitted.
Sessions, a self-described hard-core conservative, said he is not looking over his right shoulder in case of a Republican primary opponent.
"But it is true that a challenge would come to me from my right, not my left," he said.
Democratic Rep. Eddie Bernice Johnson, who is retiring after nearly three decades in Congress, said while gerrymandering has always existed, it has gotten more extreme thanks to technology, such as computer programs that allow state legislatures to be more precise in drawing districts for partisan gain.
"We need lines that would force us to talk with each other, that force us to share ideas and understandings. The way these lines are being drawn now, it doesn't compel a person to look outside of their party lines," she said.
With the help of computers, the lines are now being drawn "where they can be so exact that they can break up a bedroom if they wanted to," she said, adding, "It is hurting our nation."
Kimball Brace, who is hired by states across the country to draw their maps, has one of those computer programs. He showed us just how advanced the technology is.
"By the time you get down to the census block level, you can end up getting exact populations for any given piece of geography," Brace said, demonstrating on one of his redistricting computer programs.
Gerrymandering takes place in states where Democrats control the legislature as well as those led by Republicans.
In Maryland, for example, Democrats are in charge and drew a new map that Republicans say unfairly disenfranchises GOP voters and gives the Democratic majority in the state House and in the congressional delegation more power.
Republican Kathy Szeliga, a delegate in the General Assembly, is a plaintiff in a lawsuit against the new maps. She alleges that the map was gerrymandered to crack Republican voters, robbing them of the opportunity for fair representation in the state House and US House.
Standing in the State House in Annapolis, Szeliga pulled out two maps -- one with jagged lines that she said are drawn to protect Democratic incumbents and one drawn by an independent Citizens Redistricting Committee, which is a nonpartisan approach.
"A fifth grader can look at these two maps next to each other and say what looks fair and what looks (like) it was created with partisan purposes," she said.
CNN requested interviews with members of the Maryland Democratic leadership and members of the redistricting committee. None agreed to speak with us.
"When you let politicians draw their own maps, be they Republican or Democrat, they're going to hold onto their power. They're going to covet their power and they're going to protect it," Szeliga added.
There are a lot of ideas on how to fix the persistent and growing problem of gerrymandering. States like California, under the pressure of GOP former Gov. Arnold Schwarzenegger, created the kind of commission that Szeliga and Maryland Republican Gov. Larry Hogan advocate. Lines are drawn in California by the commission, not by the elected state legislature. There was a commission after the 2020 census in Michigan and Virginia, but it is too soon to tell how much of an impact these have on partisan gerrymandering in those states.
Hurd advocated an idea he admits isn't likely to get much traction, which is to draw congressional districts with the goal of making them politically competitive.
"The most important thing to happen would be (to) create competition in more seats, because that is going to force people to work together to actually solve problems."
But for now, when states like Texas are going from 12 competitive US House districts to just one, Congress will likely become even more polarized.
"You're going to see more dysfunction," Hurd predicted.
"Because you could have even less people working together."
CORRECTION: An earlier version of this story misstated what the Constitution says about House seat apportionment and how states redraw congressional districts.