Republicans

Twelve Republican senators broke party ranks to side with Democrats, approving a proposal to revoke the proclamation by 59-41.

The Democratic-controlled House of Representatives last month backed the measure.

Following Thursday's vote, Mr Trump tweeted: "VETO!"

Congress needs a two-thirds majority of both chambers to override a presidential veto, which is viewed as unlikely in this case.

Nevertheless, the vote will be seen as an embarrassing loss for the president on his signature domestic issue.

The bill now heads to the Senate where it faces daunting challenges because of the same ideological splits between conservative and moderate Republicans that nearly killed it in the House.

Trump said he is confident the bill will pass the Senate, calling Obamacare "essentially dead."

"This is a great plan. I actually think it will get even better. This is a repeal and replace of Obamacare. Make no mistake about it," Trump said at a celebratory White House appearance with House Republicans.

The Republican National Committee (RNC) sets out in its Rule 9 the terms for "filling vacancies in nominations".

It reads: "The Republican National Committee is hereby authorized and empowered to fill any and all vacancies which may occur by reason of death, declination, or otherwise of the Republican candidate for President of the United States."

Death may be off the agenda, so what about the other scenarios?

Declination...

"He knew, or he should have known, that what that man was asking was not only way out of bounds, it was untrue," Hillary Rodham Clinton, the Democratic front-runner, said after a campaign event in New Hampshire. "He should have from the beginning repudiated that kind of rhetoric, that level of hatefulness."

The question to Trump came Thursday night at a town hall in Rochester, New Hampshire. The first person the billionaire real estate mogul called on said, "We have a problem in this country. It's called Muslims."

The Republicans said this is despite the State Department's pledge to produce 5,000 new pages of documents.

A spokesman for Rep. Trey Gowdy of South Carolina said Tuesday that "nothing has changed" since Gowdy balked Saturday at an announcement by Clinton's presidential campaign that she would testify Oct. 22 before the panel. Gowdy chairs the special committee.

In some of his first commentary on the budding race to replace him, Obama accused the candidates of violating a time-honored American tradition of not playing "fast and loose" on topics of grave concern like foreign policy. 

And he said that regardless of which party wins the White House, he wants to ensure he's turning over the keys to someone capable of seriousness and honesty.

But Trump simply may not care; indeed he seemed to bask in his McCain takedown.

After dismissing McCain's reputation as a war hero because he was captured in Vietnam and "I like people who weren't captured," Trump declared "I will say what I want to say." He insisted he would stay in the GOP primary field, despite rivals who say he's now shown he doesn't merit the presidency.

In Iowa on Saturday, Trump said that he doesn't consider McCain, a prisoner of war in the Vietnam War, to be a war hero.

The front-runner for the Democratic nomination, Hillary Rodham Clinton, not only harshly criticized Trump during a campaign event in Arkansas, she accused the GOP field of being slow to repudiate Trump's other controversial statements.

Several 2016 contenders have brushed off Trump's comments while others have ignored them. Marco Rubio, a Florida senator who is Hispanic, denounced them as "not just offensive and inaccurate, but also divisive," after declining for two weeks to address the matter directly. Another Hispanic in the race, Ted Cruz, said Trump is "terrific," ''brash" and "speaks the truth."

It's an uncomfortable moment for Republicans, who want more votes from the surging Latino population.