Jeb Bush could be making his last stand in South Carolina on Saturday.

The Republican desperately needs to do better in the third voting state than he has so far to convince both donors and voters that he is still a viable presidential candidate.

Bush, the brother and son of former presidents, got just 3 percent support in Iowa’s caucuses earlier this month and 11 percent support in the New Hampshire primary.

He is competing with Marco Rubio, a senator, and John Kasich, the governor of Ohio, for the support of moderately conservative voters who need to coalesce around a single candidate to defeat Ted Cruz and Donald Trump.

Rubio

Bush’s popularity nationwide has been under 5 percent since December, the RealClearPolitics average of polls shows.

He is polling neck and neck with Rubio, his main rival, in South Carolina. NBC News argues that Bush can’t afford to place behind the senator he only narrowly bested in New Hampshire.

This week, Rubio won the endorsement of the state’s popular governor, Nikki Haley, and he is once again being played up in the media as the favorite to unify the party.

That could become a self-fulfilling prophecy.

Politico reports that several longtime donors are preparing to “intervene and tell Bush, depending on his finish here Saturday night, that his time is up.”

“If he finishes significantly behind Rubio in South Carolina, I think a lot of the people who are personally close to him, including donors are going to say, don’t stay in until money runs out, don’t stay in just to be a spoiler,” one said.

Road ahead

The primaries immediately following South Carolina’s don’t look particularly favorable to Bush.

Most of the “Super Tuesday” states that vote on March 1 are in the South, including Texas. Cruz, who represents Texas in the United States Senate, is likely to do well, given that Southern states are more socially conservative than the rest of the country.

So might Rubio, who has started emphasizing his faith in South Carolina.

But unlike Rubio, Bush’s campaign has been preparing for a long nominating contest. It knows that states that vote later in March and in April will probably prefer a moderate. Florida and Ohio, important swing states in the general election, will hold primaries then, as will Democratic-voting states like Connecticut and New York.

The question is if Bush can hold on for so long.