(CNN) When a group of 22 senators negotiates a $1 trillion bill, conversations can go off track. And when they did — "far too many (times) to recount," joked one senior staffer — Arizona Sen. Kyrsten Sinema would urge them to finish the job, even if that required some liquid courage.
"I would say, 'it is unacceptable for us to give up here,'" she told CNN. "Have a glass of wine."
And so, after months of negotiating, the group toasted this week to striking the largest infrastructure deal since the Interstate Highway System, making investments in public transit, passenger rail, clean drinking water, bridges, and electric vehicles that the White House said were either the largest ever or in several decades.
The agreement is the crest of Sinema's eight-year career in Congress. As the lead Senate Democratic negotiator, she has been in regular contact with Biden by phone or seated across from him in the Oval Office.
But for some Democrats, Sinema's bill is far from enough, noting that it comprises about a quarter of President Joe Biden's initial American Jobs Plan, which included much greater incentives for research and development, manufacturing and clean energy.
These progressives said that Sinema's bill advancing through the Senate now is just the latest offense, after she publicly defended the filibuster and opposed the price tag of a $3.5 trillion bill expanding the social safety net.
Steven Slugocki, the former Democratic Party chairman for Arizona's Phoenix-based Maricopa County, said that while Sinema promised to "get stuff done," she "has so far not held up to those promises" and said the bill "doesn't go far enough for what this historic opportunity calls for."
"Her constituents are frustrated, disappointed and angry — and rightfully so," Slugocki said. "Voters are looking for leadership and action, not upholding old unnecessary Senate traditions. The time for real results has come."
Sinema has, however, earned rapturous praise from many of her colleagues; the deal's $550 billion in new federal spending united business and labor groups like the Chamber of Commerce and AFL-CIO.
But the applause for Sinema appears to be louder from the right than the left. The title of a recent op-ed from Sen. Thom Tillis, a North Carolina Republican, is: "Senate infrastructure deal is a win for bipartisanship, thanks to Sen. Sinema." The Arizona Republic editorial board, which before Donald Trump only endorsed Republican presidents, took on the left in a new op-ed, writing that "perhaps it's time for the fire-breathers to reconsider that maybe, just maybe, the first Democrat to win a U.S. Senate seat in Arizona in 30 years actually knows what she is doing."
Garrick Taylor, a top official at the Arizona Chamber of Commerce, told CNN that the bill included a number of wins: expanding access to high-speed internet, upgrading border stations along the US-Mexico border and improving technology to aid water management. The state Chamber tweeted a "thank you" to Sinema, noting that the bill doesn't increase taxes on "job creators."
Sinema's relationships with Republicans proved to be a crucial when Senate Majority Leader Chuck Schumer announced he would force a vote to get on the bill last week, before they had written it or even struck an agreement.
Republicans blasted the decision, saying the group wasn't ready. Without the support from 10 Republicans, the bill was stuck. Asked by reporters what she was going to do, Sinema said she simply was going to keep working as if nothing had really changed.
"What other people do is less important than what we do," she said.
Alaska Republican Sen. Lisa Murkowski, a member of the bipartisan group said that Sinema played a vital role in advancing the talks.
"There were several times when we got bogged down and started relitigating things that had been resolved a long time ago — and she basically just said 'stop,'" said Murkowski. "She called it out."
The White House also came to appreciate Sinema's approach. In the first weeks of the administration, Biden's team worked to get a read of the first term senator, according to multiple officials. She simply wasn't as well-known of a commodity as West Virginia Sen. Joe Manchin of West Virginia, another critical, centrist Democrat in the 50-50 Senate, they said. But her role in the Democratic caucus was no mystery.
"It's been pretty clear from Day One that we always need to make sure we know where Sen. Sinema is, no matter the issue," said one administration official.
A test came in January, when Vice President Kamala Harris conducted local television interviews in West Virginia and Arizona to tout the emerging Covid relief legislation. It was perceived by Democrats on Capitol Hill to be a deliberate effort to press Sinema and Manchin to support the legislation. Manchin quickly voiced his displeasure with the administration for failing to reach out to him in advance. Sinema, notably, said nothing in public.
That decision was noted inside the White House, and served as a window into what has been a key piece of her relationship with Biden: she will share her views and, critically, ensure the White House won't be surprised by her position on an issue. It just won't show up in the press first.
It's an approach, officials say, shared by Biden, who never wavered from his direct assurances to Sinema that he was committed to the bipartisan talks and would see them through -- even as progressive Democrats increasingly urged him to end them when an outcome appeared in doubt.
The President reached out in person or on the phone to her at key points throughout the infrastructure negotiations: when Biden's initial talks with Republicans broke down, when a framework was about to be struck in June and when Biden appeared to throw that agreement into doubt by tying its passage to a separate, sweeping $3.5 trillion bill.
When the negotiations floundered this week, Sinema was once again in the Oval Office. The deal was reached on Wednesday.
"Throughout the negotiations, Senator Sinema was candid and transparent with the bipartisan group and the President," White House spokesman Andrew Bates said in a statement to CNN. "She showed determination at every stage, working to keep everyone in the room and focused on the goal."
It's a dynamic that will only become more critical in the weeks ahead, as the White House and Democratic leaders press to navigate the arduous intraparty battles that will determine whether the entirety of the President's sweeping agenda can get across the finish line. Biden, for his part, has always been candid with Sinema about how integral he views the second piece of that agenda, packed with progressive priorities, for the country.
While Sinema, 45, is now reaping plaudits from the right, her career began two decades ago working for the Green Party during Ralph Nader's 2000 presidential run. She then became a pink tutu-wearing anti-war activist, and lost her first bid for the Arizona House as an independent in 2002. She then ran as a Democrat in 2004 — and won — and served there until 2010 before jumping up to the state Senate.
Alejandra Gomez, a progressive activist at the Arizona Center for Empowerment, told CNN that she remembered when Sinema brought her pizza in 2010 as she was organizing a protest against a state bill that let police check a person's immigration status if there was a "reasonable suspicion" that the person was illegally in the United States. Critics said the bill led to racial profiling.
"This is a very different Sinema from the Sinema that was with us protesting SB 1070 in 2010," said Gomez, a reference to a strict immigration law in Arizona that energized many Democratic activists in the state to protest the measure. "Just to see this transformation has been incredibly disappointing."
In 2012, Sinema ran for a competitive House district in suburban Phoenix, won and joined centrist committees in Congress. She voted against California Rep. Nancy Pelosi as House Democratic leader and built a reputation of working across the aisle on the Financial Services Committee.
But she also had a background that appealed to the Left, as she rose from her impoverished roots, and in 2018, Sinema became the first Democrat in Arizona to be elected senator since Dennis DeConcini was reelected in 1988. She's also the state's first senator to be a woman, to be openly bisexual and to describe her religion as "none."
Her victory speech heavily alluded to the late Arizona Republican Sen. John McCain, who died months before her election, and she now spends a significant amount of time during votes hobnobbing with her Republican colleagues rather than sitting with those in her own Democratic caucus.
In some ways, Sinema's blunt style and propensity to take on her own party emulates McCain.
But her centrist positions have infuriated some Democrats, who say the state faces a series of crises — water shortages, climate change, evictions—that she's not up to facing.
Sinema is one of the most outspoken members when it comes to preserving the filibuster, which prevents radical change by forcing 60 votes for most legislation. The image of her thumbs-down vote to raising the minimum wage as part of a massive pandemic aid bill in March also drew the ire of the left.
And she's come out swinging against passing a $3.5 trillion bill that would fund climate initiatives, universal prekindergarten and community college, establish paid family and medical leave, expand the child tax credit, and add dental, vision and hearing benefits to Medicare, among many other proposals. She is open to passing the budget but not a bill that costs that much.
"I thought there was agreement among Democrats, but evidently not," said Massachusetts Sen. Elizabeth Warren.
Some Democrats are looking for someone to run a campaign against Sinema when she runs for reelection in 2024.
"If we need to find a new candidate, we are prepared to do so as Arizonans," Gomez said.
A few strategists who helped launch New York Rep. Alexandria Ocasio-Cortez's 2018 upset campaign have already set their sights on the senator through a new PAC called No Excuses. Corbin Trent told CNN that the PAC plans on airing radio and digital ads next week.
"We're going to start ramping up and making sure folks are aware of just how little she gives a damn to not just Arizona, but this country," Trent said.
CORRECTION: An earlier version of this story misspelled Kyrsten Sinema's first name.