5 things to watch in New Hampshire's primary

Former South Carolina Gov. Nikki Haley's presidential campaign faces a major test of electability in New Hampshire's Republican primary on Tuesday, when, polls show, she has her best chance to put a dent in former President Donald Trump's chances of clinching a third straight presidential nomination.

Haley is leaning on turnout from independents who can vote in the primary to boost her to a win or a close second to Trump, which, she has said, would fuel her momentum until next month's primary in her home state of South Carolina. But a more expansive victory by Trump could pump the brakes on Haley's argument that she is a viable alternative.

While Haley has closed the gap with Trump in New Hampshire, somewhat, 538's polling average shows Trump up by more than 30 points in South Carolina.

On the other side, Joe Biden's allies are working to gin up support for a write-in campaign for the president, who is not appearing on the ballot in the state's unsanctioned Democratic primary. Despite the odd circumstances of the race, a win against Biden for either Minnesota Rep. Dean Phillips or author Marianne Williamson would mark an embarrassment for the incumbent — a scenario many leading Democrats in New Hampshire are hoping the write-in effort will avoid.

Here are 5 things to watch in Tuesday's races.

Haley's campaign and allies have been bullish that she's set for a win or narrow second-place showing. But a bad loss, following a weak showing in Iowa's caucuses last week, could spell the beginning of the end for the South Carolinian.

Challenger Ron DeSantis, who did slightly better than Haley in Iowa, ended his own campaign on Sunday after he said he didn't see a chance of success in the coming races.

With 538's polling average still