Scenes From March 5 Election Contests

Mitt Romney said on Friday morning that he would do "everything within the normal political bounds" to keep Donald Trump from becoming the Republican nominee.

It was a jaw-dropping moment in a campaign that's been full of surprises from the beginning. Romney has spoken out against Trump, but has yet to endorse another nominee.

Mr Rubio had taken issue at Mr Trump's habit of calling him "Little Marco" as they battle to win the Republican nomination.

Coming on the heels of big victories for Trump on Super Tuesday, tonight might be the last chance for one of Trump's rivals to curb the frontrunner's momentum.

"And you know what they say about men with small hands?"

The Republican senator said Trump 'has offended personally every single person running for president, he's offended journalists, he's offended the disabled, he's offended women.

"Donald is telling us he will betray us on everything he's campaigned on", he said as he campaigned in ME, one of five states voting in weekend primaries and caucuses. Think of all the damage that will be done if Hillary Clinton and the Democrats are elected, they say.

For all of the criticism and ill will, Cruz, Rubio and John Kasich all said they would support Trump if he is the Republican nominee.

"Oh, no. Please", Rubio said. I predict that he told the New York Times that his immigration talk is just that: "talk... let us hear what he said behind closed doors to the New York Times".

The debate, being held in the northern city of Detroit, was filled with the same yelling, personal insults and off-color remarks that have featured prominently in the 2016 Republican race for president. To watch Republicans and conservatives wrestle with this question is to understand how political parties die and how democracies give rise to authoritarian rulers.

During Thursday's debate, Trump told Kelly she's "looking well", and said it was nice to be at the event with her.

Trump has won ten states and continues to dominate the conversation and the delegate count.

Randy Barnett, a professor at Georgetown University's law school, has proposed that Cruz and Rubio form a partnership, with each pledging to support the other at the convention. That would not secure the nomination for any of them, but it would prevent Trump from amassing the 1,237 delegates he needs for a first-ballot nomination.