It was one thing in 2016 for top Republicans to take a stand against Donald Trump for president: He wasn’t likely to win anyway, the thinking went, and there was no ongoing conservative governing agenda that would be endangered. Donald Trump in a blue sky: US President Donald Trump points as he boards Air Force One at Bangor International airport in Bangor, Maine, on Friday. © NICHOLAS KAMM US President Donald Trump points as he boards Air Force One at Bangor International airport in Bangor, Maine, on Friday.

The 2020 campaign is different: Opposing the sitting president of your own party means putting policy priorities at risk, in this case appointing conservative judges, sustaining business-friendly regulations, and cutting taxes — as well as incurring the volcanic wrath of Trump.

But, far sooner than they expected, growing numbers of prominent Republicans are debating how far to go in revealing that they won’t back his reelection — or might even vote for Joe Biden, the presumptive Democratic nominee. They’re feeling a fresh urgency because of Trump’s incendiary response to the protests of police brutality, atop his mishandling of the coronavirus pandemic, according to people who spoke on the condition of anonymity to disclose private discussions.

Former President George W. Bush won’t support the reelection of Trump, and Jeb Bush isn’t sure how he’ll vote, say people familiar with their thinking. Senator Mitt Romney of Utah won’t back Trump and is deliberating whether to again write in his wife, Ann, or cast another ballot this November. And Cindy McCain, the widow of Senator John McCain, is almost certain to support Biden but is unsure how public to be about it because one of her sons is eyeing a run for office.

None of them voted for Trump in 2016, but the reproach of big Republican names carries a different weight when an incumbent president and his shared agenda with Senate leaders are on the line.

Former Republican leaders like the former speakers Paul Ryan and John Boehner won’t say how they will vote, and some Republicans who are already disinclined to support Trump are weighing whether to go beyond backing a third-party contender to openly endorse Biden. Retired military leaders, who have guarded their private political views, are increasingly voicing their unease about the president’s leadership but are unsure whether to embrace his opponent.

Biden himself, while eager to win support across party lines, intends to roll out his “Republicans for Biden” coalition later in the campaign, after fully consolidating his own party, according to Democrats familiar with the campaign’s planning.

The public expressions of opposition to Trump from parts of the Republican and military establishment have accelerated in recent days over his repeated calls for protesters to be physically constrained, “dominated,” as he put it, and his administration’s order to forcefully clear the streets outside the White House so he could walk out for a photo opportunity. His conduct has convinced some leaders that they can no longer remain silent.

Former Defense Secretary Jim Mattis’s blistering criticism of Trump and the admission this past week by Senator Lisa Murkowski of Alaska that she is “struggling” with whether to vote for the sitting president of her own party have intensified the soul-searching taking place, forcing a number of officials to reckon with an act they have long avoided: stating out loud that Trump is unfit for office.

“This fall, it’s time for new leadership in this country — Republican, Democrat, or independent,” said William H. McRaven, the retired Navy admiral who directed the raid that killed Osama bin Laden. “President Trump has shown he doesn’t have the qualities necessary to be a good commander in chief.”

McRaven, making his first public comments opposing Trump’s election in an interview on the 76th anniversary of D-Day, noted that those wartime leaders inspired Americans with “their words, their actions, and their humanity.”

In contrast, he said, Trump has failed his leadership test. “As we have struggled with the COVID pandemic and horrible acts of racism and injustice, this president has shown none of those qualities,” McRaven said. “The country needs to move forward without him at the helm.”

Trump won election in 2016, of course, despite a parade of Republicans and retired military officers who refused to support him. Far more current GOP elected officials are publicly backing Trump than did four years ago. Among his unwavering supporters are Republican leaders like Mitch McConnell, the Senate majority leader, and past foes like senators Ted Cruz and Lindsey Graham. And polls today indicate that rank-and-file Republicans are squarely behind the president, although that is in part because some Republicans who can’t abide Trump now align with independents.

Yet it would be a sharp rebuke for former Trump administration officials and well-known Republicans to buck their own standard-bearer. Individually, they may not sway many votes — particularly at a time of deep polarization. But their collective opposition, or even resounding silence, could offer something of a permission structure for Trump-skeptical Republicans to put party loyalty aside.

John Kelly, Trump’s former chief of staff and a retired Marine general, would not say who he would vote for, though he did allow that he wished “we had some additional choices.”

Dan Coats, a former Republican senator who was Trump’s director of national intelligence, “has been concerned about the negative effect on the intelligence community by the turmoil of turnover at DNI,” said Kevin Kellems, a longtime adviser to Coats, adding that the former spy chief is “encouraged by the confirmation of a new DNI and career intelligence deputy.”

As for the candidate for whom Coats will vote, “ultimately he remains a loyal Republican but he believes the American people will decide on Nov. 2,” Kellems said.