Pennsylvania Sen. John Fetterman has been threatening to leave the Democratic Party. He has no right to do so. My column this week in the Pittsburgh Jewish Chronicle.If Fetterman became a Republican, it would be nearly impossible for Democrats to win a Senate majority in 2026.

By Bruce Ledewitz July 29, 2026, 9:58 am

It seems to be open season for Democratic Party politicians in Pennsylvania. First, in May, Pennsylvania Supreme Court Justice David Wecht announced he was leaving the Democratic

Party to become a registered independent because, in his view, the party had become tolerant of antisemitism. Then, in July, U.S. Sen. John Fetterman threatened to leave the Democratic Party if it became an “anti-Israel” party, specifically referencing an arms embargo bill sponsored by Democrats in the House. Fetterman did not say whether, if he left the party, he would become an independent or register Republican.

Wecht’s announcement provoked criticism, mostly because as a jurist he should not enter into political issues. But no one doubted Wecht’s right to leave the Democratic Party. After all, Wecht’s decisions as a judge, like those of all judges, are always to be strictly non-partisan. In a sense, it should not matter what political party a judge belongs to once that judge joins the bench.

Fetterman’s situation is different. He was elected by voters as a partisan act to reflect partisan differences. Not only was Fetterman elected because he was a Democrat, he was elected to serve the interests of the Democratic Party in the U.S. Senate. By running as a Democratic candidate in 2022, Fetterman was promising each voter that he would serve as a Democrat in the Senate until 2028. That is why Fetterman, unlike Wecht, has no right to leave the Democratic Party and still remain in office.

This can easily be understood if we imagine Fetterman becoming a Republican. When I voted for him in 2022, it was not just a vote for Fetterman personally. It was also a vote to try to maintain a Democratic Party majority in the Senate, which narrowly succeeded that year. In the coming midterms, there is a small chance that the Democrats will retake the Senate majority. I voted for Fetterman on the assumption that he would vote to maintain a Democratic majority every two years. If Fetterman became a Republican, it would be nearly impossible for Democrats to win a Senate majority in 2026. Thus, by changing parties Fetterman would be undermining a sovereign decision that only the voters have a right to make.

People tend to forget how important majority control of the Senate is. If Democrats had consistently controlled the Senate in President’s Trump’s first term, the U.S. Supreme Court would not have a conservative majority. If Democrats retake the Senate in the 2026 midterms, Trump will be unable to appoint a justice should a vacancy occur.

Majority control of either the House or the Senate means that the leadership of that party determines the legislative agenda of that branch of Congress. Because Republicans controlled the Senate in 2016, Judge Merrick Garland’s nomination to the U.S. Supreme Court by President Barack Obama did not come to a vote. Because Republicans controlled the Senate in 2020, Amy Coney Barrett was confirmed to the court after the death of Justice Ruth Bader Ginsburg despite the imminence of an election that Trump lost.

The importance of majority control is why Democrats in Maine are so determined to oust GOP Sen. Susan Collins despite her quite reasonable voting record. Collins votes to give Republicans the majority in the Senate. All of this is why Fetterman would be betraying the voters if he became a Republican.

But what if Fetterman did not actually change parties? What if he left the Democratic Party but became a registered independent and voted to give the Democrats the majority in the Senate if circumstances allowed? That is what Arizona Sen. Kyrsten Sinema did in 2022 and West Virginia Sen. Joe Manchin did in 2024. They were elected as Democrats and then caucused with the Democrats after switching to independent status. What if Fetterman became an independent who caucused with the Democrats?

This action would still be a betrayal of the voters, as it was for Sinema and Manchin. Unlike Joe Lieberman and Bernie Sanders, who were elected to the Senate as independents, Fetterman was elected to the Senate as a Democrat. When I voted for him in 2022, I was not just voting for him to work in the Senate. I was also voting for him to be a voice for me in the national Democratic Party. I have a right to insist that he continue to be that voice.

It is true that support for Israel was not a big issue in 2022. I did not know how Fetterman felt about Israel. In fact, Fetterman has taken numerous positions that his supporters would not have expected and often disagree with. There is nothing dishonorable or unusual in that. Aside from particular campaign promises on specific actions and issues, our elected representatives are expected to use their best judgment about the needs of our country. You elect a person to public office in part because you respect their judgment in terms of future issues. Disagreeing with your constituents can sometimes be a badge of honor.

Nevertheless, when I voted in 2022, I was trusting Fetterman to be a voice in the Democratic Party. I have a right to that voice even if I do not agree with what he has to say. Fetterman would be betraying that trust if he left the Democratic Party. And that is the case even though the polls tell us that most Democrats want Fetterman to leave the Democratic Party. He made a promise to each voter, not to Democrats in general.

As it happens, I agree with Fetterman on something like an arms embargo, even though I am probably more critical of Israel than he is. What is even more important, however, is that it would not serve America’s interests, nor those of Israel, if there really were two political parties in America, one pro-Israel and one anti-Israel. It is very important that Fetterman remain in the Democratic Party and continue an intra-party debate over America’s relationship with Israel.

If fact, I think it is important that both parties contain both supportive and critical views about Israel. Important foreign policy issues should not become strictly partisan. America’s long-term foreign policy commitments are not supposed to change every time we vote the other party into office.

If Fetterman feels too offended by what some Democrats are doing to remain in the party, he is always free to resign from the Senate. In threatening to leave the party, Fetterman is treating his office as if it were his property. He is forgetting that he was elected as a representative.

There is one additional aspect to Fetterman’s position. He might change parties or become an independent to set up a run for reelection in 2028. It is a given that Fetterman would have little chance of surviving a Democratic Party primary for his Senate seat and it is equally clear that if he announced he was running for reelection as a Democrat, there would be a primary. So, Fetterman might prefer to run as an independent or as a Republican.

Fetterman has every right to pursue either course. But to keep faith with the voters from 2022, he has to wait. I am entitled to his vote and his presence in the Democratic Party until his term ends. What Fetterman does then will create a new set of allegiances, expectations and obligations. If he were to run in 2028 as a Republican or an independent, and were successful, then he would owe those voters the same fidelity that he owes to us now. PJC

Bruce Ledewitz is professor of law emeritus at the Thomas R. Kline School of Law of Duquesne University. The views expressed in this article do not reflect those of Duquesne University.