Why Manchin's retirement is Democrats' worst nightmare

A Democratic fairy tale is coming to an end in West Virginia, where Sen. Joe Manchin's decision not to seek re-election threatens to blow up the party's chances of holding the Senate — and potentially the White House — in 2024.

Why it matters: Without Manchin — widely viewed as the only Democrat who could run competitively in deep-red West Virginia — Republicans likely will need to flip just one or two Senate seats to take control of Congress' upper chamber, depending on the outcome of the presidential race.

• Perhaps more alarming for Democrats, Manchin's announcement left open the possibility that he would run for president on a centrist third-party ticket.
• "What I will be doing is traveling the country and speaking out to see if there is an interest in creating a movement to mobilize the middle and bring Americans together," Manchin said in a video statement.

The big picture: The conservative Democrat, who's been in the Senate since 2010, will leave behind a complicated legacy.

• Manchin frequently butted heads with Democratic leadership, especially in recent years as his influence reached its peak in the narrowly divided chamber.
• He never shied away from criticizing President Biden's agenda or threatening to tank Democratic legislation and nominations, even flirting with the idea of becoming an independent as the infighting mounted.
• But without Manchin, Biden never would have passed his signature legislative achievement — the Inflation Reduction Act, a $740 billion package that featured the largest climate investment in U.S. history.

Between the lines: The massive spending bill took a sledgehammer to Manchin's image back home in West Virginia, and disputes with Biden over its implementation have increasingly left him on a political island.

• Facing long odds in next year's Senate race, Manchin has toyed with the idea of running on a bipartisan presidential ticket sponsored by No Labels, which praised him in a vague statement reacting to his retirement.
• In July, Manchin shot back at Democratic criticism that he would be a "spoiler" candidate who could help elect former President Trump: "If I get in a race, I'm gonna win," he said.

What to watch: There are no obvious Democratic successors to Manchin, and West Virginia Gov. Jim Justice was already favored to win the Senate race next November assuming he becomes the GOP nominee.

• With Manchin's seat firmly in the Republican column, Sens. Jon Tester (D-Mt.) and Sherrod Brown (D-Ohio) — the other two red-state Democrats up for re-election — will move further into the political spotlight.
• "This officially makes us Mitch McConnell's number one target. You can bet that every dollar national Republicans would have spent in West Virginia is now coming to Montana," Tester said in a fundraising appeal.

The upside: Abandoning a West Virginia race that already was tilting red will free up Democratic resources to defend incumbents and go on offense in Texas and Florida — the only potential pick-up opportunities.