After a year of fretting about President Biden’s political standing and their electoral chances in 2024, Democrats are at a moment of high confidence as Republicans prepare for their first presidential debate on Wednesday.

They will be watching with bated breath in hopes that the Republican candidates embrace the likely-to-be-absent Donald J. Trump, defend him over his four criminal indictments, endorse national restrictions on abortion and — in the Democrats’ dream scenario — call for cuts to Social Security and Medicare.

Even without Mr. Trump onstage, Democrats see the Republican White House hopefuls as avatars for what they describe as a party in thrall to its extreme elements. Nobody is rooting for the debate to go off the rails more than Democrats praying for Mr. Biden’s re-election.

“All I want these people to do is say the same stuff they’ve been saying on the campaign trail on national TV,” said Jim Messina, the campaign manager for President Barack Obama’s 2012 re-election bid. “Please continue to double down on a six-week abortion ban. That would be wonderful. Thank you for doing this.”

Mr. Biden probably won’t watch the debate, a spokesman said, but odds are that his compatriots will. Here’s what Democrats are looking for from the Republicans on the debate stage in Milwaukee.

Will they rally around a national abortion ban? Since the Supreme Court overturned Roe v. Wade last summer, Democrats have used the abortion issue to turbocharge their voters — particularly in red and purple states like Kansas, Wisconsin and, this month, Ohio.

Nothing would make Democrats happier than to see Republicans embrace a national ban on abortion during a nationally televised debate. When Mr. Trump held a CNN town hall event in May, the moment that had Democrats doing cartwheels afterward was not his continued denial of the 2020 election results, but when he took a victory lap for the Supreme Court’s decision.

“I’d like to see a huge defense of President Trump and a full-on assault on reproductive freedom and abortion,” said Gov. Phil Murphy of New Jersey, a Democrat. “To me, that would be a gift that would keep on giving.”

In reality, many of the Republican candidates have tended to be more cagey about the issue.

Mr. Trump, at the CNN event, declined to call for a national abortion ban, and Gov. Ron DeSantis has also treaded carefully despite signing a six-week prohibition into law in Florida this year. But avoiding the subject may be tricky given former Vice President Mike Pence’s enthusiastic support for limiting abortion rights.

How much do Republicans cozy up to Trump? Mr. Trump probably won’t be at the debate, but Democrats expect nearly all of the candidates onstage to make explicit plays for his share of the Republican base — a move Democrats hope will focus attention on their own efforts to brand the entire G.O.P. as the party of MAGA.

“It doesn’t matter who ‘wins’ the debate on Wednesday, the MAGA Republican presidential candidates have all chosen a losing strategy that is extreme and out of touch with the American people,” Michael Tyler, the communications director for Mr. Biden’s campaign, wrote in a memo to supporters on Friday.

Mr. Biden has for months been on a mission to paint all Republicans as marching in lock step with Mr. Trump’s most loyal, hard-right supporters. On Wednesday, Democrats are hoping to see Republicans engaged in stylistic efforts to attract Trump voters.

“I’m a wrestling fan,” said Jaime Harrison, the chairman of the Democratic National Committee. “I’m imagining a royal rumble on the debate stage, sort of a rehash of the debates in 2016 where they’re talking about each other’s mamas and all kinds of craziness.”

But one lesson that has been abundantly clear in the Trump era of politics is that no other Republican can get away with the type of outrage and public shamelessness that Mr. Trump regularly evinces. Mr. DeSantis’s efforts to be a drama-free, more competent version of Mr. Trump have flopped so far. Vivek Ramaswamy, the biotech executive who has sought to portray himself as a millennial version of Trump, has risen in early polling but remains largely unknown.

Will the Trump indictments be a focus?

The biggest story about Mr. Trump is the one Mr. Biden won’t talk about — the four criminal indictments the former president is facing.

The problem for the Republicans running against Mr. Trump is that many of their voters agree with his belief that the cases against him are politically motivated.

Democrats on the sidelines have been left waiting, to little avail, for Mr. Trump’s G.O.P. rivals to make a case to their voters that the legal problems are politically disqualifying.

“Normally candidates would be more than happy to point out if their opponent has been indicted four times!” Senator Amy Klobuchar of Minnesota wrote in a text message. “They ARE running against him after all.” That plea is unlikely to get much airtime on Wednesday. Of the candidates onstage, only former Gov. Chris Christie of New Jersey — who is running an anti-Trump campaign that has won him new respect from Democrats — has made an explicit case that Mr. Trump’s indictments have merit and are bad for the party.

What about Hunter Biden?

One thing the Republican candidates are all but certain to do is equate Mr. Trump’s legal problems with those of Hunter Biden, the president’s son, who is facing his own special counsel investigation after a plea agreement on tax and gun charges fell apart last month.

Democrats aren’t exactly popping popcorn for this scenario — it is an intensely painful episode for the president, and the prospect of a criminal trial isn’t appealing to them — but they are confident that any detour down a Hunter Biden rabbit hole will take emphasis away from issues that moderate and independent voters care about.

“If Republicans want to make this election about attacks on the president’s family, it’s a losing strategy,” said Gov. J.B. Pritzker of Illinois, a Democrat. “It would be a mistake for them to make that an issue.”

Democrats hope to dispel the fiction that it won’t be Trump.

Democrats widely view Mr. Trump as the easiest Republican candidate to defeat next year. Mr. Biden beat him once already, they reason, and Mr. Trump’s cascading legal problems and singular ability to repel moderate Republicans and swing voters make him the one they’d like to face.

Mr. Trump’s dominance in polls of the Republican primary and the reluctance of most of his G.O.P. rivals to attack him have led most Democrats to conclude that Wednesday’s debate, along with much of the primary, is an academic exercise being held before next year’s Trump-Biden rematch.

“I was just going to watch it for comic relief,” said Representative Jasmine Crockett, a Texas Democrat. “This is done. We are going to have Trump versus Biden 2.0. That’s what’s about to happen. Anyone who is kidding themselves into believing that they have a shot is just delusional.”

And for the cast of candidates who barely qualified for the Republican stage, hoping that a standout debate performance would propel them to relevance — a TV show, a future cabinet post or maybe a campaign for some other office — a former presidential long shot had a piece of advice.

“Learn how to count to 200,” said Representative Eric Swalwell of California, who, many people may have forgotten, ran for the Democratic presidential nomination in 2020. “Because that’s about the amount of seconds that you’re going to have to speak.”