The dam broke open Tuesday morning as several Senate Democrats urged their colleague Sen. Bob Menendez (D-N.J.) to resign.

Most notably, a trio of vulnerable Democratic senators joined the calls for Menendez to go, a sign that their indicted colleague is already becoming a liability for their 2024 reelection campaigns.

Within the span of an hour, Democratic Sens. Jon Tester (Mont.), Tammy Baldwin (Wis.) and Bob Casey (Pa.) separately released statements saying Menendez needs to step down as he faces federal corruption charges.

“I’ve read the detailed charges against Senator Menendez and find them deeply disturbing,” Tester tweeted. “While he deserves a fair trial like every other American, I believe Senator Menendez should resign for the sake of the public’s faith in the U.S. Senate.”

Minutes earlier, Baldwin tweeted a similar message about Menendez, who was indicted Friday on charges that he and his wife took bribes ― including $100,000 in gold bars, $480,000 in cash and a Mercedes-Benz ― in exchange for favors that aided an Egyptian American businessman and others.

“The indictment spells out deeply troubling allegations against Senator Menendez that breach the American people’s trust and compromise his ability to effectively represent his constituents,” Baldwin said. “While Senator Menendez enjoys the presumption of innocence until proven guilty and will have his day in court to defend himself, I believe it’s best for his constituents, the American people, and our national security for the Senator to step down.”

Casey issued a statement saying that the allegations against Menendez indicated that repeatedly violated the public’s trust.

“While he is entitled to the presumption of innocence, serving in public office is a privilege that demands a higher standard of conduct,” said the Pennsylvania Democrat. “Senator Menendez should resign.”

Tester, Baldwin and Casey join a fast-growing number of Senate Democrats urging Menendez to go. The others are Sens. John Fetterman (Pa.), Peter Welch (Vt.), Sherrod Brown (Ohio), Elizabeth Warren (Mass.) and Jacky Rosen (Nev.), who is also up for reelection in 2024.

What’s clear about this particular group of senators speaking up is that the New Jersey Democrat’s refusal to resign is becoming a problem for the party. The National Republican Senatorial Committee on Monday issued a statement tying vulnerable Democrats up for reelection in 2024 to “crooked” Menendez.

“You’d think it would be a no-brainer to say someone who took gold bars from foreign businessmen to rig US foreign policy is unfit to serve in the Senate, but apparently Senate Democrats disagree,” NRSC spokesman Philip Letsou said in the statement. “Democrats have made clear they will tolerate Bob Menendez’s comical levels of corruption as long as he continues to back their extreme agenda.”

Which Democrats did the NRSC single out? Tester, Baldwin, Brown and Casey.

Some Democratic senators are still reluctant to pile on. During a Tuesday interview on MSNBC’s “Morning Joe,” Sen. Debbie Stabenow (D-Mich.) was asked if she thinks Menendez needs to go.

“As far as I’m concerned, we will let this move forward this week and we’ll see what happens,” Stabenow said.

“So, not yet for you,” said the show host.

“Not yet,” Stabenow replied.