In a presidential election year that was originally a rematch between two political titans but that has since been marked by a debate debacle, a candidate switcheroo, and two assassination attempts, it’s easy to forget about the other races. But as dramatic as all that has been, there’s plenty at stake in the US Senate, as well, where just a few seats one way or the other can make all the difference.

Dark Days for Democrats?

There are 34 Senate seats up for grabs in the 2024 election, and while Democrats currently hold a slight majority. That said, they also have more in jeopardy – and the consensus among at least half a dozen forecasters is they’ll lose that lead.

Right now, Democrats control 51 seats (counting four independents, two of whom aren’t running for re-election), and Republicans have 49. Of the 34 up for grabs in the 2024 election, 23 are held by Democrats or left-caucusing independents, and just 11 belong to the GOP. According to the forecasters behind 270toWin’s 2024 Consensus – the Cook Political Report, Elections Daily, Fox News, Inside Elections, Sabato’s Crystal Ball, Split Ticket, and US News – the expected outcome will be 51 seats for Republicans, 48 for Democrats, and one that’s a toss-up and could go either way.

Here’s the full breakdown of the outcome predicted by 270toWin and the various forecasters:

There are 28 Democrats who aren’t up for re-election right now and 23 who are; 14 of those 23 are considered “safe,” meaning they’re highly unlikely to be flipped red. One is considered “likely” to be won by the Democrats, with five more “leaning” that way – which accounts for all but one of the seats in play. The final prediction is 48 or 49, depending on how the race goes between Ohio’s incumbent Democrat, Sherrod Brown, and his Republican challenger, Bernie Moreno.

Republicans have just 11 seats in play, of which nine are considered safe, one is likely, and three are leaning. There are 38 red seats not up for grabs. If all those go Republican, it gives the GOP a 51-49 majority if Sen. Brown wins in Ohio or 52-48 if he doesn’t.

Also of special note are John Tester, Joe Manchin, and Kyrsten Sinema. Tester seems poised to lose his Montana seat to Republican challenger Tim Sheehy, helping flip the Senate red. West Virginia’s Manchin, who left the Democratic Party this term and isn’t running for re-election at all, was always an electoral outlier as the state’s only Democrat at the national level. His seat is also expected to go to the Republican candidate this year, Jim Justice. As far as Senate votes go, however, Manchin had often refused to toe the party line, standing firm along with Arizona’s Kyrsten Sinema – another Democrat-turned-independent who isn’t running for re-election – on issues where he felt his party’s razor-thin majority was trying to steamroll over the Republicans. Sinema’s seat is expected to remain in the hands of the Democratic Party, however, and if her replacement is more willing to go along with the team, it gives slightly more voting power to what seems likely to be a slight Democratic minority.

Statistically, things don’t look good for the Democratic majority in the Senate. Now, what will that mean going forward? Well, it largely depends on the presidential election – another race that, depending on which pollster you ask, is either a toss-up entirely or, if a prediction is made, it’s by the slimmest of margins.

The Presidential Difference

A Trump presidency with a GOP majority in the Senate would likely mean a free pass for the president to appoint whoever he wants to whatever job he wants that person to have, no matter how opposed to the appointment Democrats may be. And that could be big. Not only are we talking Cabinet positions and a variety of federal judgeships, but thanks to the tit-for-tat game both major parties have been playing for years with the filibuster, the Supreme Court is in play as well. In such a climate, it wouldn’t be surprising at all to see some of the older justices “strategically retire” to make sure Trump gets to replace them.

Clarence Thomas and Samuel Alito are the oldest (75 and 73, respectively), and either of them might wonder whether they have another four more years in them – or eight to 12, depending on how 2028 and 2032 go. A Trump win and a GOP majority in the Senate could well mean one or two retirements and new Supreme Court nominees, almost certain to be confirmed. Conversely, it would hamstring the ability of Kamala Harris to fill vacancies requiring Senate confirmation should she win instead and, for that matter, the Democratic legislative agenda.

A Republican-led Senate would also insulate Trump against the nigh inevitable impeachments that would come should the Democratic Party pull a lead in the House of Representatives. Should the House remain red – giving Republicans a trifecta government – it would likely mean a bevy of partisan lawmaking. Yes, the legislative filibuster would likely be heavily used as well, but that’s only assuming Democrats don’t end it before the new Congress is seated or that Republicans don’t end it afterward.

A Tied Senate – Now There’s Some Drama

But what if there’s a 50-50 tie in the Senate? That has happened several times in the course of the nation’s history, including as recently as 2021, which was, according to Ballotpedia, the fourth time.  Of course, whichever party controls the White House holds an effective majority in these cases – unless, for some reason, there isn’t a vice president – and that’s where things get really interesting.

Should the Senate tie, the incoming vice president – JD Vance or Tim Walz – will give his party the upper chamber majority as a tiebreaker. Most VPs never get a chance to break many ties, and the first, John Adams, held the record at 29 for half a century. John C. Calhoun broke 31 ties – and Adams’ record – from 1825 to 1832. That record stood until the current vice president and presidential hopeful, Kamala Harris. She still has a few months to go as a potential tiebreaker, but her current count stands at 33 – an impressive feat considering the previous record holders served eight years each.

Her predecessor, Mike Pence, only broke 13, and her current boss, Joe Biden, didn’t break any during his eight years as vice president. Perhaps the next VP will claim the title, whether the upper chamber goes ever-so-slightly to the right, the left, or is split down the middle. Even in a drama-filled presidential election year like this, the Senate remains a show worth watching.