Chris Christie has heard the words of everyone in the GOP telling him to back out of the Republican primary, and he has decided to respond with a 7-figure ad buy in New Hampshire.

In the ad, titled "Some People Say," Christie stands before the camera with nothing in the background, pushing back against those calling on him to step aside.

"Some people say I should drop out of this race," he says in the ad. "Really? I’m the only one saying Donald Trump is a liar. He pits Americans against each other."

The 33-second spot is a direct rebuke of both Donald Trump and the idea that Christie should withdraw from the race - a race where he struggles to gain any sort of momentum outside of New Hampshire - and even there, he's a distant third place.

The Christie campaign has made it a point to go all-in on New Hampshire despite the odds, especially when former U.N. Ambassador and South Carolina Governor Nikki Haley is far ahead of him in the state.

Christie has sharpened his response to voters who question why he stays in the race, arguing that he’s the only one taking on the GOP front-runner directly.

A recent CBS News/YouGov poll found 10% of likely GOP primary voters in the Granite State said Christie is their first choice, trailing Trump at 44% and former South Carolina Gov. Nikki Haley at 29%, but sitting about even with Florida Gov. Ron DeSantis at 11%.

In response to questions about Haley...

Haley has gained momentum and donor support recently, and Christie is under pressure to drop out of the race to consolidate the number of Trump alternative candidates. But Christie pointed out on the campaign trail last week that even if he left the race before the New Hampshire primary, not all of his supporters would necessarily back Trump’s former ambassador to the United Nations.

He told a voter at a house party in Portsmouth last week that if Haley showed him “she was actually running against Donald Trump,” then he “might” consider supporting her.

Christie's odds seem like a longshot, given the lay of the land. Former president Donald Trump has a commanding lead nationally and in most of the early states. There's also significant data showing that Nikki Haley would stand to benefit from Christie dropping out - when polled, his supporters list her as their second choice, which would put Haley over Trump in New Hampshire.

Haley's supporters, meanwhile are most likely to go to Florida Governor Ron DeSantis if she drops out, and the DeSantis voters are most likely to go to Trump if he drops out.

But overcoming Trump is first and foremost on everyone's minds. DeSantis is focusing all of his efforts on Iowa, while Haley and Christie focus on New Hampshire. But while Christie's last stand might be the northeastern state, Haley could deliver a 1-2 punch if she wins in New Hampshire and then wins her home state of South Carolina.

But everything would need to fall into place for that to happen, and it seems far from likely at this stage.

Christie maintains that he is the only one willing to stand up to Trump directly, but it's still a longshot to win one state. Does he have the ability to win more than one?