WASHINGTON - President Donald Trump's plan to kill Obamacare died last week. Or maybe it didn't.

The repeal effort seems to have assumed zombie status ? somewhere between dead and alive.

This is never-say-die Washington, where big legislative proposals that are in the casket one day can show signs of a pulse and start climbing out the next.

It's a fairly common condition in the capital, where politicians who invest enormous political capital in a proposal are loath to let go.

"One of the keys to understanding Washington is to think a little bit like a coroner," says consultant Ari Fleischer, former press secretary to President George W. Bush. "You have to know when something's dead and when something's still kicking, and sometimes it's hard to tell the difference."

To say that Trump and Republican congressional leaders are sending mixed signals about the viability of the repeal effort is an understatement.

Last week, when it became clear that House Republicans didn't have enough votes to pass the health-care repeal bill, the White House said Trump had given it his all, left everything on the field, and was ready to move on.

Next up: taxes, the president said, without blinking.

His son Eric channeled Kenny Rogers' "The Gambler" in praising his father for knowing when to walk away.

"Guess what? We're moving on," the president's son told Fox News on Tuesday. "The best business people know ... when to hold their cards, know when to fold the cards."

That same night, though, the president told a bipartisan gathering of senators, "We're all going to make a deal on health care. That's such an easy one. So I have no doubt that that's going to happen very quickly."

Trump spokesman Sean Spicer said Wednesday the president had just been engaging in light-hearted banter.

But it was no laughing matter to plenty of Republicans on Capitol Hill, where conservatives elected on a promise to scrap the law continue to insist that reports of the repeal effort's death are premature.

"We don't quit," said freshman Rep. Brian Mast, a Florida Republican who lost both legs after being wounded in Afghanistan. "That's how we do things on the battlefield; that's how things should be done here."

On Thursday, House Speaker Paul Ryan added to the cacophony of conflicting statements when he told CBS that it's time for Plan B, where "we keep talking to each other and figure out how we get to 'yes.'"

For all of that, there is little evidence that leaders are working on a concrete plan to revive the repeal effort.

Why not admit that?

It could be the emotional attachment to a long-held goal. Or a matter of self-interest.

"These are creatures that need public recognition and public validation," says Stephen Wayne, a Georgetown University professor of government. "When they get behind something and it doesn't go anywhere, or they're embarrassed by it, it's a political failure. It's an ego failure."

Framing the situation more charitably, Fleischer offers this: "People in both parties generally have a lot of heartfelt investments in the policies they're pursuing. Particularly for core promises, the formality of declaring it dead is gut-wrenching, so you cling to hope and you don't declare it dead 'til you have no choice."

There are historical examples that demonstrate both the wisdom and folly of refusing to admit defeat.

President Ronald Reagan's push for a sweeping tax overhaul package was pronounced dead on Capitol Hill more than once before a bipartisan package won approval in 1986.

President Bill Clinton's push to revamp welfare was declared a failure repeatedly before it came together. His years-long effort to remake the health care system was declared a goner more than once ? and really did die.

President Barack Obama's attempts to enact gun control measures after the 2012 shooting of schoolchildren in Newtown, Connecticut, ended with the president acknowledging in 2014 that until there was a fundamental shift in public opinion, "it will not change."

Between the clear victories and defeats lies a netherworld of legislative limbo.

Obama's push for big immigration changes stalled after the Senate in 2013 passed a bill with dim prospects of clearing the House, but the idea lived on in people's hopes and dreams. All the discussion of whether immigration reform was dead or alive was a pretty good indication that it was the former.

Obama never explicitly acknowledged the political reality that the Trans-Pacific Partnership trade deal was dead after Trump was elected. The White House just stopped actively lobbying Congress to pass it.

Obama's day-one vow to close the U.S. detention center at Guantanamo Bay in Cuba became increasingly less likely to succeed over his eight years in office. But he never admitted it was a promise unfulfilled until his last full day in office.

Robin Wagner-Pacifici, a sociology professor at the New School for Social Research, said there may be parallels to military surrenders, which fell into disuse in the latter part of the 20th century to be replaced by "conflict resolution or dispute resolution or accords of various kinds that had a much more fuzzy quality to them."

She said it may also be partly a matter of Trump's fragmented and sometimes contradictory ways of communication, in which "nothing is ever completely resolved or ended."-AP