Democratic senators are crushing their GOP opponents in the money race. They’re still likely to lose their majority.

But since August, poll after poll has shown Tester trailing Sheehy by several points, a result not seen before in the senator’s previous re-election bids in 2012 and 2018.

The culprit may be the ongoing decline in “ticket-splitting,” a phenomenon where citizens vote for candidates from different political parties during the same election. For example, a Montanan may vote for Tester in the Senate race, but choose Trump in the presidential race.

This used to be more common, and there used to be more instances of Democrats representing conservative states and Republicans representing blue states. But as polarization and partisan sorting have intensified over the last several election cycles, a growing share of the electorate is simply voting for one party all the way down the ballot.

Still, Tester could pull it out, and there are signs that some Trump voters are still are planning to back the Democratic senator: Tester consistently polls well ahead of Harris in Montana.

Super PACs — and rich candidates funding their own campaigns — have helped the GOP make up some of the gap

There’s one competitive Senate race where the Republican slightly outraised the Democrat — Wisconsin, where Eric Hovde brought in $11.2 million to Sen. Tammy Baldwin’s $11 million.

But that was only possible because Hovde, a wealthy businessman, poured $7 million of his own money into his campaign in August and September.

It’s part of a broader strategy that Republicans have employed during this election cycle, relying at times on their own candidates’ wealth to fund their campaigns.

In Pennsylvania, Republican candidate Dave McCormick has loaned his campaign nearly $4.3 million to his campaign since the race began. Sheehy and Moreno have also contributed millions to their campaigns.

There’s also “outside spending” — money spent by groups on behalf of each candidate that aren’t officially connected to either campaign.

Both Democrats and Republicans have super PACs for Senate races, and they’re running roughly even in fundraising. Republicans’ “Senate Leadership Fund” raised $115.7 million in the most recent period, while Democrats’ “Senate Majority PAC” raised $119 million.

That sort of spending can make a big difference in key races, with Ohio being a key example. In addition to the super PAC spending from Democratic and Republican groups, the Buckeye State has also seen a deluge of spending from “Defend American Jobs,” a super PAC with ties to the cryptocurrency industry.

Brown, the chair of the Senate Banking Committee, has been a crypto critic, and the pro-crypto group has now spent upwards of $40 million on ads promoting Moreno, his GOP opponent.

Polling has so far broadly shown Brown leading Moreno, a striking result given that, like Montana, Trump handily won the state twice.

But the polls have tightened in recent weeks, and if Moreno defeats Brown, Democrats will have virtually no chance of retaining the majority — and crypto money will have played a key role.