Washington (AP) — Donald Trump wants more than acquittal. He wants vindication.

With impeachment by the House appearing certain, the president has made clear that he views the next step, a trial in the GOP-controlled Senate, as his focus. The president sees the senators not just as a jury deciding his fate, but as partners in a campaign to discredit and punish his Democratic opponents. His Senate allies aren't so sure that's a good idea.

In recent weeks, Trump has devised a wish list of witnesses for the Senate trial, relishing the opportunity for his lawyers to finally cross-examine his accusers and argue the case that his actions toward Ukraine, including the July 25 call when he asked for a favor, were "perfect."

Trump and his allies have been building up the likely Senate trial, an effort to delegitimize the Democratic-controlled House's impeachment process by contrast. In the Senate, the Trump team has argued, the president would get the opportunity to challenge witnesses and call some of his own, such as House Intelligence Committee Chairman Adam Schiff, the still-anonymous intelligence community whistleblower, or even Joe Biden and Hunter Biden.

He sees that as a chance to embarrass Democrats, including the former vice president and 2020 Democratic rival, and use the friendlier ground to portray himself as the victim of a partisan crusade.

"It is pretty clear the president wants a trial," says Hogan Gidley, the principal deputy White House press secretary. "The president is eager to get his story out."

But it is increasingly clear that Senate Republicans, led by Majority Leader Mitch McConnell, have other ideas. McConnell, who is fiercely protective of his 53-47 Senate majority, has signaled that he wants none of the spectacle Trump desires. Instead he wants a swift trial, potentially with no new witnesses called.

"Here's what I would anticipate: The House managers would come over, make their arguments, the president's lawyers would then respond. And at that point the Senate has two choices," McConnell told reporters this week. "It could go down the path of calling witnesses and basically having another trial. Or it could decide -- and again 51 members could make that decision -- that they've heard enough."

In other words, the president, who is almost certain to be found not guilty by the Republican-controlled Senate, can win the hard way or the easy way.

Senate Trump allies and advisers inside the White House have in recent days urged the president to temper his expectations and choose the path of least resistance. But Trump, according to three people familiar with the conversations, has responded by repeating his desire for a politically charged trial that drags the Bidens and others into the impeachment spotlight. Still, some aides believe Trump will ultimately relent to McConnell's advice.

Trump's solicitation of Ukraine for investigations into the Bidens — while withholding military aide from the ally nation facing Russian aggression — forms the core of one article of impeachment against the president. His efforts to block the House investigation forms the second.

On Capitol Hill, the emerging GOP consensus is that doing Trump's defense his way would jeopardize a predictable outcome, test GOP's fragile loyalties to him and open a Pandora's Box of unanticipated consequences.

"People are beginning to realize that could be a pretty messy and unproductive process," Sen. Ron Johnson, R-Wis., said Wednesday. "If you start opening up to witnesses, you start opening up to all witnesses. And so I think the president's got to really decide, to what extent does he want to start going down that road versus just making a strong case."

Democrats would be expected to retaliate by trying to call the president's senior-most advisers, including acting chief of staff Mick Mulvaney and Secretary of State Mike Pompeo, and his personal attorney, Rudy Giuliani.

Under Senate rules, McConnell's ability to control the proceedings are limited. The Chief Justice of the United States, John Roberts, presides over the trial and any senator may be able to put a motion on witnesses up for a vote. That means defections by just a few GOP senators could thwart McConnell's plans.

With the Republicans slim majority, it's not at all clear they want to start down the path of a full-blown trial. Should they try to call the whistleblower or the Bidens to testify, they may not find enough votes of support from their ranks. At the same time, they would have to consider whether to accept or fend off witness requests from Democrats.

McConnell also worries that a prolonged impeachment trial would not benefit the handful of GOP senators setting out in the new year on potentially tough reelection bids. Swing state Sens. Susan Collins in Maine, Cory Gardner in Colorado, Joni Ernst in Iowa and Martha McSally in Arizona are among those whose actions will be closely watched. They would much rather be talking about the economy or the pending U.S.-Mexico-Canada trade agreement than engaging in a prolonged, unpredictable impeachment trial.

But Republicans also acknowledge they are unlikely to find the 51 votes needed to dismiss the charges against the president outright. Some vulnerable lawmakers and Trump skeptics, such as Sen. Mitt Romney of Utah who has said he is troubled by Trump's actions, will insist on some semblance of trial.

Comparisons are being made to the confirmation of Brett Kavanaugh to the Supreme Court, in which the Senate had to deal at length with allegations of sexual misconduct, though his confirmation by the Republicans was becoming increasingly apparent.

"I think the American people are pretty tired of this," says Sen. Pat Roberts, R-Kan. "I think if we can honor the White House's concern, OK. But let's do it in a reasonable time limit. We don't need six weeks like we did with Clinton."

Around the White House, a divide has emerged between aides and allies embracing the president's call to use the Senate trial to get back at Democrats and those, particularly in the White House counsel's office, advising him to heed the warnings of the GOP lawmakers.

On Wednesday, senators invited some of Trump's top House allies, including Rep. Jim Jordan of Ohio, to lunch to provide an overview of the case. And lawmakers huddled last week with top White House officials to caution against a path toward an explosive Senate trial.

McConnell says no decisions have yet been made, and the Senate's calendar for the new year has conspicuously left off the schedule for January. McConnell's task in the days ahead will be to survey his conference and work with the president to find common ground.

—-

AP writer Alan Fram contributed.

Follow Miller and Mascaro on Twitter at https://twitter.com/ZekeJMiller and https://twitter.com/LisaMascaro