(CNN) We're one day out from Election Day. Democrats are hoping to hold on to power, while Republicans yearn to gain control of both the House and the Senate. And while we all have guesses of what will happen, the truth is that we don't know what will play out.
With that uncertainty in mind, here are five different scenarios that could be key to how the battle for control shakes out.
Stop me if you have heard this one before. If you follow politics to any degree, you certainly have. Unlike other states with close Senate races, Georgia requires candidates to receive a majority of the vote to win on Election Day. If no candidate does, then a runoff between the top two candidates is held in December.
The conditions are fairly ripe for such a scenario. Neither Democratic Sen. Raphael Warnock, nor Republican Herschel Walker is at 50% in the Georgia Senate polls. Libertarian Chase Oliver is pulling in 3% to 4%.
If every other race goes exactly as the polls predict, Democrats will have 49 seats not including Georgia. Republicans will have 50 seats. This means that whichever side wins in Georgia would control the Senate.
Then there's the other side of the spectrum. Most people are anticipating that we won't know who wins the Senate until days, if not weeks, after Election Day. That may be the case, but it's far from a certainty.
There are a few ways we could conceivably get a fairly fast call. The easiest way for it to happen is if the Republicans win both Georgia (with a majority to avoid a runoff) and Pennsylvania. That way, we're probably not reliant on what could be longer counts in Arizona and Nevada.
Another way this might happen is if there is a surprising result in the east. If Republicans have a very good night, they could win the New Hampshire Senate race, where Democratic Sen. Maggie Hassan is running for reelection against Republican Don Bolduc. If Democrats have a very good night, they could win the Ohio Senate race, an open seat where Democratic Rep. Tim Ryan is facing off with Trump-endorsed J.D. Vance.
Even if we're not able to project the Senate quickly, surprising results like that will give us a strong idea of which way the wind is blowing.
If the race for the House is tighter than expected, then mail voting could play a major role.
Specifically, states like California, Oregon and Washington that feature heavy mail voting. This can delay the vote count, especially in California, where ballots only need to be postmarked by Election Day and the law allows for an extended period of vote counting.
In 2018, the election in California's 21st District wasn't decided until December 6, nearly a month after the November 7 election, because of the ballot count.
This year, there are at least 9 House races on the west coast that look like they could be close. When you combine these with Alaska's at-large seat (which features both mail and ranked choice voting), it's not hard to see how things could take a while to call.
Just weeks ago, the race for both the House and Senate looked close. While the Senate still does, it's easy to see how the House could turn into a relative blowout.
If that happens, we won't have to wait for the west coast. We won't have to wait for the results from ranked choice voting races.
Instead, we'll get a pretty good idea from even the earliest of poll closings. Consider a race like that for Virginia's 2nd District, a swing district centered in Virginia Beach. Rep. Elaine Luria would likely win if Democrats are to be competitive in the House. If she's defeated, Republicans are probably on their way to House control.
If it's a big Republican night, we could also see Democratic Rep. Frank Mrvan go down in Indiana. Indiana, unlike a lot of other states, requires voters to have an excuse to vote absentee.
The bottom line is that if Republicans end up with close to 240 seats (as they did in 2010), then the race for House control won't be drawn out.
My guess is that this one won't actually happen given Republicans' momentum on the generic congressional ballot. Still, it is a statistical possibility that the House ends up being really tight.
There are two states (Alaska and Maine) that have ranked choice voting. This allows voters to rank the candidates on their ballot from most to least favorite. If no candidate is the top choice of a majority of voters, then the supporters of the candidate with the fewest number of first round votes have their votes reallocated to their second choice. This sequence continues until one candidate has a majority of votes.
The House race for Alaska's At-Large District -- a seat that was held by Republican Don Young for decades before he died and was replaced by Democrat Mary Peltola -- and Maine's 2nd Congressional District -- the state's lone swing district -- are expected to be competitive. Both have had past elections where ranked choice voting determined a House winner.
The use of ranked choice voting requires that all ballots be counted to properly figure out whether more than one round is needed and the order of elimination for the candidates in those rounds.
This took until nine days after the election for Maine's 2nd District in 2018. In Alaska, it takes 15 days for ranked choice voting results to be known.