Daniel M. Shea is the Marson-Moller-McNulty Professor of Government at Colby College.

Sen. Susan Collins wants to talk about her bipartisanship, an understandable strategy.

Maine leans blue, and few states value political moderation as much. Even as ticket splitting has nearly disappeared across America, many Mainers pride themselves on judging candidates rather than parties. Collins has built an entire Senate career on that instinct.

The go-to retort from Democrats is that Collins’ votes against her party are rare and, more importantly, strategic. She gets a pass from Republican leadership only after a measure’s success has been assured, or she votes for the procedural motions that decide a bill’s fate and against final passage once the outcome is settled.

So, what’s the skinny on Collins’ bipartisan record? As they say, it’s complicated.

The Lugar Center’s Bipartisan Index has ranked her at or near the top of the chamber year after year, and she has broken with Republican presidents on a few highly visible issues. At the same time, CQ Roll Call found that Collins supported President Trump’s position roughly 95% of the time in 2025.

Those facts are not contradictory. They reflect how much the Senate has changed. In today’s Congress, a senator who defects a handful of times per session can be deemed “the most bipartisan.” But has the definition of “bipartisan” also shifted? It has.

When Collins’ career began, moderate Republicans were part of the Senate’s fabric. Maine alone sent Bill Cohen and Olympia Snowe to Washington. Across the country, Republicans like John Chafee, Nancy Kassebaum, Mark Hatfield and Warren Rudman worked with Democrats to write legislation, broker compromises and assemble governing coalitions. No one called them bipartisan because they voted against their party here and there. They were bipartisan because they helped govern across party lines. They forged compromise solutions. That is a different model from the one Collins represents today.

Yes, the Senate has become much more polarized. The ideological overlap between the parties has nearly vanished, and genuine coalition-building is harder than it was in 1996, when Collins was first elected. In the new environment, moderation has come to mean something smaller. Instead of asking whether a senator can build bipartisan agreements, we ask whether she occasionally casts a dissenting vote. Those are not the same thing.

The old moderation changed legislation before it reached the floor. Today’s version of moderation usually amounts to dissent after decisions have been made. Collins sometimes casts votes against her party. Where the outcomes stay the same, the dissent makes little difference.

Maine watched this play out last summer. The Medicaid cuts in the 2025 budget law were drafted in committees chaired by the majority and moved on the majority leader’s schedule. Collins voted “no,” warning of what the cuts would mean for Maine’s rural hospitals. The bill became law anyway. Her dissent was real, but it changed nothing, because the decisions that mattered had already been made.

Which brings us to the most consequential vote Susan Collins has cast every two years, and will cast again if she returns to Washington. It comes before any debate over taxes, immigration, spending or judges — before the Senate takes up any legislation at all. It is the vote to organize the chamber: the vote that elects the Senate leader.

That single decision shapes every important vote that follows. Every senator casts the “organizing vote,” and no one crosses party lines. If reelected, Collins will vote for Republican leadership, a move that cannot be spun as moderate, bipartisan or centrist.

Collins would answer, fairly enough, that the organizing vote is exactly what makes her chair of the Appropriations Committee, and that the gavel delivers for Maine.

But the same organizing vote gives Ted Cruz the committee that oversees Maine’s fisheries, and it puts public lands and conservation policy under Mike Lee, who spent last summer trying to sell off millions of acres of the kind of land Collins helped protect with the Great American Outdoors Act. It hands the Special Committee on Aging — the committee Collins herself chaired for six years — to Rick Scott, whose 2022 plan would have sunset all federal laws, Social Security and Medicare included, every five years.

Some of the most strident Republican partisans in the Senate now run the committees Maine depends on. The chairmanship is the payment for the organizing vote, and the price includes every other chairman it installs — not just Collins. There is nothing bipartisan about it.

There is also no getting away from the fact that if the organizing vote puts Republicans in charge, it empowers Donald Trump’s agenda.

None of this makes Collins’ bipartisan claims unimportant. It makes them incomplete. Voters should weigh the times she has stood apart from her party — and ask what difference those votes made in the end. And they should weigh her pending vote to install a Republican majority. She’d be chair of Appropriations, but Trump and his hardcore partisans would be in charge of the rest.

For 30 years, Collins has asked Mainers to vote for the candidate, not the party. The first vote she casts in Washington does the opposite, and Maine voters should be clear-eyed about that.