We have seen a curious phenomenon emerge as the past two spending bills supported by the Trump administration wound their way through Congress: Sen. Susan Collins was one of a handful of Republicans to vote against them — and they passed anyway.

In and of itself, this isn’t particularly surprising. To the consternation of Maine Republicans, Collins is often at odds with her own party. One often sees comments from conservatives that the state and/or national Republican Party should rein her in. Luckily, that’s not the function of political parties in this country. The function of American political parties is to elect members of their own party to office, not to enforce ideological purity in any way, shape or form. Many members of the public, even those who have been involved in politics, don’t seem to grasp this. If you want your elected officials to vote a certain way, it’s up to you to get involved and put the pressure on them to do so.

What’s interesting about Collins’ votes against the rescissions bill was that it fell completely under the jurisdiction of the committee that she chairs, the Appropriations Committee. In the past, the senator would have been able to singlehandedly block the measures. U.S. senators ran committees like personal fiefdoms, and the Senate Appropriations Committee was — and still is — one of the more powerful ones. Being chair of that committee was one of the most powerful positions outside of actual leadership.

While it’s still an important, powerful position, it’s not nearly as powerful as it used to be. In the case of the rescissions bill, the Senate voted — with Vice President JD Vance breaking the tie — to discharge it from committee, bringing it directly to the floor. Democratic efforts to send it back to committee failed. The same happened with the “big, beautiful bill,” albeit with the Senate Finance Committee. It’s actually a good thing that committee chairs aren’t as powerful as they used to be; for years, committee chairs blocked civil rights legislation.

So, Collins couldn’t block the rescissions bill, and her vote opposing both bills wasn’t enough to stop them simply because the Republicans have such a large majority in the U.S. Senate.

Republicans have their largest majority since 2015-2017, when they had 54 seats and Barack Obama was president; the last time they had a majority this large with a Republican president was from 2005-2007, when George W. Bush was president and they held 55 seats. During that Congress, they also passed a reconciliation bill that cut spending without the support of either of Maine’s U.S. senators at the time, Collins or Olympia Snowe. That bill, too, passed thanks to a tie-breaking vote from the vice president, then Dick Cheney. So, we’re seeing history repeat itself.

What’s different is the circumstances: Maine now only has one Republican U.S. senator, and she’s chair of the Appropriations Committee. While that’s good for Maine, as it allows Collins to steer quite a bit of federal funding our way, it doesn’t grant her the unilateral authority to block federal legislation. So, instead, she did as much as she could to improve the legislation, but in the end it wasn’t enough to get her to vote for it.

Again, this wasn’t a matter of anyone “allowing” her to vote a certain way, as is often alleged. Leadership and the White House count votes, but they also always want the votes of every Republican. The administration and leadership no doubt worked hard to secure Collins’ vote, and would have preferred to have it; no president wants his legislation opposed by members of his own party.

We’re not done with major fights over spending this year; we may have a chance to see this new dynamic play out again. Congress is facing a tough deadline to fund the federal government by Sept. 30. Muscling through the recent bills won’t make bipartisan negotiations over the budget easy, and Collins’ committee will be right at the center of this debate.

Without a doubt, Sen. Collins will try to forge a bipartisan solution. It will be interesting to see whether or not she’s able to get this done. If she can’t, the question becomes whether she’ll support the final product, or whether we’ll see a repeat of Vance casting the tie-breaking vote. Hopefully the two sides can come to some sort of agreement. As with prior legislation, Collins can’t make it happen nor scuttle it singlehandedly.