Sen. Joe Manchin III (D-W.Va.) has thrown up a roadblock to much of President Biden’s policy agenda. Writing in the Charleston Gazette-Mail, Manchin made plain over the weekend that he would oppose Democrats’ signature voting rights measure, the For the People Act. What’s more, Manchin once again declared that he would never vote to weaken or end the filibuster, complicating Democrats’ path to securing top policy priorities.

Why is Manchin such a thorn in his fellow Democrats’ sides?

Here’s what you need to know.

It’s not easy being blue (in such a red state)

Former president Donald Trump secured 68 percent of the vote in West Virginia in the 2020 election, all but matching his high of just under 70 percent in Wyoming last fall. That means Manchin represents the reddest state of any of his Democratic colleagues. Even Sen. Jon Tester (D-Mont.), who represents the next-reddest state, only faces an electorate that gave Trump 57 percent of the vote.

Nearly 50 years ago, political scientist David Mayhew wrote about the importance of the “electoral connection” for understanding what makes lawmakers tick. Reelection, Mayhew argued, was every legislator’s immediate goal. No matter what other goals might motivate them, none of their ambitions — policy or otherwise — can be achieved if they are not first reelected.

As Occam’s razor would suggest, Manchin’s electoral environment back home best accounts for why he is out of step with much of the Senate Democratic caucus on voting rights and why he’s willing to block at least some of his party’s top priorities. As the only Democrat holding statewide office in West Virginia today, Manchin’s electoral future is precarious.

True, he has had a long electoral career back home, starting in the state legislature and advancing to secretary of state and governor before his 2010 election to the U.S. Senate. But in 2018, facing both Republican Patrick Morrisey and Libertarian Rusty Hollen, Manchin was reelected with just under 50 percent of the vote. What’s more, Manchin outperformed Trump’s 2016 vote in just two of West Virginia’s 55 counties. He even trailed the president in his home county. That’s hardly a recipe for reelection in 2024.

Manchin cooks in his own ‘home style’

Being a thorn in his party’s side fits Manchin’s “home style” — a concept coined by the late political scientist Richard F. Fenno Jr. to capture how lawmakers present and explain themselves back home. By “home style,” he means the image legislators project back home, how they allocate time, staff and energies, and how they explain Washington activities to voters. A successful home style can secure voters’ trust. Trust, in turn, can make it easier for lawmakers to explain controversial votes to constituents. Losing those connections may make senators more prone to defeat.

Manchin’s home style comes through clearly in his campaign ads: shooting a copy of the Democrats’ 2010 cap-and-trade bill; riding his Harley through West Virginia countryside; blaming both parties for deadlock; but also attacking the Republican lawsuit to strike down Obamacare. He presents himself, in other words, as opposing partisan agendas all around.

That home style comes through again when Manchin wrote in his recent op-ed, “I have always said, ‘If I can’t go home and explain it, I can’t vote for it.’” Manchin’s critics questioned the logic of refusing to support election reform while Republicans restrict voting rights in the states. But his weak electoral position back home coupled with a home style that decries partisan agendas helps account for his move to undermine Democrats’ plans.

Giving his moderate colleagues political cover

This wasn’t the first time Manchin publicly opposed having either party change the filibuster by using the “nuclear option" — that is, reinterpreting Senate rules by a simple majority vote. He opposed Democrats’ move to ban nomination filibusters in 2013 and also opposed Republicans’ similar rule changes in 2017 and 2019 — making him the only current senator to have voted against both parties’ efforts. As he said in 2019, “For the life of me, I can’t figure out how anyone who voted for this will explain it when they go home. How do you look the people who elected you in the eye and say, ‘I gave up my individual power to represent you?’”

By reiterating that he won’t provide the critical 50th vote to curtail filibusters, Manchin might be giving some political cover to Democratic colleagues who remain on the fence about that, such as Sens. Jacky Rosen (D-Nev.), Angus King (I-Maine), Christopher A. Coons (D-Del.) and Tester. Vocal opposition from Manchin and Sen. Kyrsten Sinema (D-Ariz.) takes the nuclear option off the table at least for now, potentially lessening pressure on their colleagues to choose sides.

Manchin did not, however, reject using filibuster-proof budget tools to advance Democrats’ policy agenda. True, Manchin continues to insist that Biden and his colleagues seek Republican support for Democrats’ priorities, including the proposed infrastructure bill. But advancing infrastructure through budget reconciliation — circumventing the need for GOP votes — remains on the table.

Will Manchin slam that window shut as well? Stay tuned.