This is sort of the mark of a campaign that is running out of ideas:

The best hope of the Republican establishment just a week ago, Marco Rubio suddenly faces a path to his party’s presidential nomination that could require a brokered national convention.

That’s according to Rubio’s campaign manager, Terry Sullivan, who told The Associated Press that this week’s disappointing performance in New Hampshire will extend the Republican nomination fight for another three months, if not longer. It’s a worst-case scenario for Rubio and many Republican officials alike who hoped to avoid a prolonged and painful nomination fight in 2016.

“We very easily could be looking at May — or the convention,” Sullivan said aboard Rubio’s charter jet from New Hampshire to South Carolina on Wednesday. “I would be surprised if it’s not May or the convention.”

The public embrace of a possible brokered convention marks a sharp shift in rhetoric from Rubio’s top adviser that could be designed to raise alarm bells among Republican officials. Yet days after a disappointing fifth-place finish in New Hampshire and looking up at Donald Trump in next-up South Carolina, Rubio’s presidential ambitions are truly facing growing odds.

It could very well come down to this, but embracing a convention fight… and assuming that the winner of that fight would not be the top vote-getter… seems, to me, to be an incredible and unnecessary admission of weakness.

The fact is that unless Rubio does well in South Carolina, he may not be able to sustain a campaign beyond the end of March. Right now there is no evidence that Rubio is going to fight his way into one of the top two positions in the field if the contest is drawn out to the convention. And a so-called brokered convention that dipped to the third or fourth place candidate for the nomination would raise cries of a fix and set off a civil war in the GOP that would carry Hillary Clinton into the White House easily.

Rubio still has time to come back from his disappointing start, but having senior staff concede that they cannot win the nomination is not a way to inspire either voters or donors.