Dana Milbank: After Biden, Ryan’s moment is coming.

Joe Biden kept his dignity. Will Paul Ryan be able to do the same?

The two top Irish-Americans in politics have been the stars of Indecision 2015, this fall’s double bill of painful public agonizing.

Many Democrats had been urging Biden, already a heartbeat from the presidency, to run for the top job. Many Republicans have been encouraging Ryan, who unsuccessfully ran for Biden’s job in 2012, to run for speaker of the House, second in line to the presidency.

Biden, mourning his son’s death, wavered and waffled — until it was too late. On Wednesday in the Rose Garden, with his wife and President Obama on either side, Biden finally silenced the months-long drumbeat in the press — and spared himself the ordeal of having his final chapter in public life be a nomination defeat at the hands of Hillary Clinton.

“As my family and I have worked through the grieving process, I’ve said all along … that it may very well be that that process, by the time we get through it, closes the window on mounting a realistic campaign for president …,” the vice president said. “I’ve concluded it has closed.”

Ryan’s Hamlet routine is more complex: The job is his for the asking, but it may not be worth having if he’s only going to be mowed down by GOP hardliners the way John Boehner and Kevin McCarthy were. Wisely, Ryan said Tuesday night that he would take the job under certain conditions — and if he sticks to those demands, he, too, can survive this autumn of indecision with his reputation intact.

Ryan said House Republicans must agree to rules changes “that ensure we don’t experience constant leadership challenges and crisis.” And he vowed that “I cannot and I will not give up my family time.”

The lawmaker, like Biden, seemed at peace with his position Wednesday, joking with NBC’s Luke Russert about the correspondent’s name for Ryan’s requirements: “The Paul Ryan Prenup.”

The key prenup provision: Ryan’s determination to eliminate the “motion to vacate the chair” — the tool used to push Boehner into retirement. This is how just 30 Republican hooligans, by threatening to join Democrats in ousting the speaker, can force their will on the entire Republican caucus.

Alas, Ryan already seems to be wavering on this demand. Though colleagues say he told them he wants to eliminate such motions, his spokesman later said Ryan merely wants a “change to the process.”

The holdouts are digging in. “Yeah, that’s a nonstarter,” said Rep. Raul Labrador, R-Idaho, arguing, like many of the hardliners, that Thomas Jefferson authored the motion to vacate and that “if it was good enough for Jefferson, it’s got to be good enough for Paul Ryan.”

The pushback is a taste of what’s to come if Ryan takes the job. The hard-liners hit Ryan — a conservative himself who would dismantle much of the federal entitlement system — with anything they could find. They even condemned his desire to see his family.

“I really want to hear from Paul how much the speaker’s position adversely affects his personal life,” said Rep. Mo Brooks, R-Ala. “He has young children. He does not have time to do the speaker’s job as it has been done in the past.”

Said Rep. Tim Huelskamp, R-Kan.: “You can’t do the job 9 to 5. The speaker has to work on weekends.”

If Ryan doesn’t back down from his requirements — and there’s no guarantee he’ll stay firm — he may benefit from the hard-liners’ disarray; several of them interviewed Wednesday morning were uncertain about what to do. If they accept Ryan’s motion-to-vacate demand, they won’t be able to threaten him. If they refuse, they’ll marginalize themselves and give what remains of GOP leadership a license to work with Democrats.

This may be why the outgoing Boehner cheerfully predicted at a news conference Wednesday morning that Ryan would prevail. “What’s Plan B?” CBS’ Nancy Cordes asked.

“Don’t know,” Boehner replied.

Biden went with his own Plan B on Wednesday. He has long wanted to be president but he bowed to reality. “Unfortunately, I believe we’re out of time, the time necessary to mount a winning campaign for the nomination,” he said. It was the right decision, and it allows Biden to end his long public life on his terms.

Ryan now has a similar chance to resolve his indecision with integrity: He can ascend to the speakership if he can restore the office’s credibility — or he can walk away.