According to a recent analysis by Pew Research Center, there are 17 states that have never had a female Senator. After today's races are called, women could be elected to the Senate for the first time in Delaware, Indiana, Utah, New Mexico and Rhode Island. Of these women, Lisa Blunt Rochester, a Democrat in Delaware, is most favored, winning 98 in 100 simulations in our forecast. The other women running to be their state’s first senator are all longshots in their respective races, but include Democrats Valerie McCray in Indiana and Caroline Gleich in Utah, and two Republicans: Nella Domenici in New Mexico and Patricia Morgan in Rhode Island.

The US Senate currently stands at just 25% female representation.

Here's a good example of overreacting to a small sample of results from another Indiana election ...

Results are starting to trickle in from the first few counties in Indiana and Kentucky! However, they're incomplete, and it's far too early to draw any conclusions from them. My general rule of thumb is to wait until at least 10% of the expected vote is reporting before taking those numbers seriously.

On election night, information overload is almost unavoidable. With this in mind, 538 is here to offer you a guide for knowing whether a state might be in play as votes are tallied. We estimated county-level benchmarks for every state (save Alaska, which doesn't report votes by county) to offer a back-of-the-envelope gauge for how the election is going.

The benchmarks estimate what percentage of the vote Democrats or Republicans would need in each county for a statewide race to be roughly tied. That means if a candidate is performing consistently better than their party's benchmark as we get a meaningfully large number of returns (keeping in mind that the partisan split from early returns may shift significantly as the count continues), it's a decent sign that contender is on track to come out ahead in the final results. In the interactive, you can look for any state or county in the search bar above the map.

To explore how to use the benchmarks, let's take a look at one of the key swing states, Pennsylvania. On its state page, you'll find a county-level map and a table with benchmark figures, along with the share of the statewide vote that each county contributed in the 2020 presidential race. Above the map, you can toggle between the statewide races, choosing among president, Senate and governor (where applicable). And above the table, you can toggle between viewing benchmarks by margin (how much a candidate leads by) or by party vote share (what percentage of the vote each candidate has).

The map displays both the benchmark margin and the 2020 share of the vote from each county. The bluer a place, the more Democratic it would be in the case of a statewide result that's about tied, and vice versa for red and more Republican. And, the larger the bubble over a county, the more votes it contributed in the 2020 presidential election.

Take Philadelphia. Heavily Democratic, it contributed nearly 11% of Pennsylvania's statewide vote in 2020, so it's represented by a big, blue bubble. Based on our benchmark, we can expect the statewide result to be very close if Harris is leading in Philadelphia by about 62 percentage points (80% to 18%). If she's doing a bit better than that, it could signal that she's running ahead of where she needs to be in order to win; if she's doing a bit worse, it could be a sign that Trump has an edge in the state.

Of course, you should never rely on just one data point as determinative. Instead, you'll want to consider what the returns are saying across a large number of counties, and only once a large portion of the vote has come in from each of those places. Additionally, you might look at a place like Erie County in the state's northwest corner, which has a reputation for being one of the state's bellwethers. Tellingly, our benchmark there is basically a tie, so if one candidate is running a few points ahead, that is probably a good sign for them.

We hope these numbers prove to be a helpful shorthand for who might be leading in close races as the returns come in. And even in the uncompetitive states, they could provide a hopeful Republican a sense of what it would take for their party to carry California in this day and age, and a hopeful Democrat a clue as to what their party would need to compete in South Dakota!

After voting for the Democratic candidate in each presidential election since 1992, Pennsylvania narrowly flipped into Trump's camp in 2016, only to swing back to Biden in 2020. But Biden won by only 1 percentage point, and the state once again looks to be extremely close this time around, with 538's final forecast of the state showing essentially a tied race.

Not coincidentally, Pennsylvania is the most-polled state in the 2024 election cycle. For one thing, its 19 electoral votes make it the largest of the seven core swing states. And because of its size and competitiveness, Pennsylvania is also the most likely "tipping-point" state in 538's presidential election forecast.

Like many of the key states this cycle, one of the main dividing lines in the Pennsylvania electorate is education, particularly among white voters. Pennsylvania's overall population is whiter than the country's as a whole: about 73% non-Hispanic white compared with 57% nationally. Within the white population is a large and notable chunk of the state's electorate: white voters without a four-year college degree, who accounted for 45% of Pennsylvania's voters in 2020, per exit polls. Nationally, this GOP-leaning group has shifted further to the right in the Trump years.

Conversely, Democrats have made gains nationally among white voters with at least a four-year college degree, and the same is true in Pennsylvania. For instance, Philadelphia's four suburban collar counties are fairly white and have nearly 30% of the state's population that is white with a college degree. Not coincidentally, the quartet has collectively trended more Democratic than anywhere else in the state in recent years, backing Obama by 10 points in 2012 and Biden by 19 points in 2020, even as the state as a whole moved to the right over that time span.

As the state's largest city, Philadelphia forms a key part of the state's electoral math. But while the city's collar counties have moved left, the city proper actually has shifted somewhat to the right, as Democrats' substantial edge there declined by about 4 points in each of the last two presidential cycles. And Black voters are a big part of the equation here: While only about 1 in 10 of Pennsylvania's voters identified as Black in 2020, nearly half the state's Black population lives in Philadelphia. And while Democrats appear to have gained in the more well-educated and affluent parts of Philadelphia, predominantly Black precincts have experienced at least a small decline in Democratic support and, also importantly, turnout rates. Recent polling suggests this could be a big concern for Harris: An average of polls in the state found her ahead 79% to 17% among Black voters, well down from Biden's advantage in 2020 of 92% to 7%, according to exit polls.

And there's more to watch in Pennsylvania than just the presidential race. First, a critical Senate race between three-term Democratic incumbent Sen. Bob Casey and Republican Dave McCormick will be key to Democrat's slim chances to hold the chamber. Casey is favored in our final election forecast, winning 72 in 100 simulations, but that still leaves a real chance for McCormick to pick up a surprise win in the state.

There's also at least three highly competitive House seats, in the 7th, 8th and 10th Districts. All of these feature incumbents representing areas that have been trending away from their party over the last few cycles. And finally, the contests for attorney general, auditor general, treasurer and control of the state House are all competitive.