Ben Carson and Donald Trump are locked in a virtual tie in South Carolina with big leads over the rest of Republican presidential field, a new poll finds.

Carson takes 28 percent in the state, while Trump scores 27 percent, according to a Monmouth University survey released on Monday.

Trump’s support has held nearly steady from the same poll in August, which found him at 30 percent. Carson, meanwhile, was at 15 percent in the previous poll and has now nearly doubled his support in the Palmetto State.

Carson has the best favorability rating in the field, with 76 percent holding a positive view of him against only 12 percent who view him negatively. Trump has a favorability rating of 58 percent and an unfavorable rating of 29 percent.

“Trump’s South Carolina support has held fairly steady, which means that Carson’s bump has actually come at the expense of almost everyone else in the field,” Monmouth pollster Patrick Murray said in a statement.

South Carolina's primary falls third after the opening contests in Iowa and New Hampshire. With so many candidates running on the Republican side, the state is more important than ever in 2016.

The poll found that there is still room for growth for all of the candidates, as only 17 percent of voters said they have firmly decided on who they intend to support.

After Trump and Carson, Sen. Marco Rubio (R-Fla.) is a distant third place in South Carolina at 11 percent, up five points from the same poll in August. Sen. Ted Cruz (R-Texas) is in fourth place at 9 percent, a four-point gain from August.

Rubio has the second best favorability rating in the field, with 58 percent having a positive view of him against 16 percent negative.

Jeb Bush is in fifth place at 7 percent support. No other candidate in the field takes more than 2 percent support.

Bush’s favorability rating is underwater, at 41 percent favorable and 43 percent unfavorable. That’s a huge negative swing for the former Florida governor, who was at 52 percent positive and 32 percent negative in the same poll from August.

In a head-to-head matchup between only those candidates considered “outsiders” — Carson, Trump, Cruz and businesswoman Carly Fiorina — Carson leads with 38 percent support, followed by Trump at 30, Cruz at 15 and Fiorina at 7.

In a hypothetical field of GOP candidates that excludes those four, Rubio leads with 32 percent support, followed by Bush at 13 percent, New Jersey Gov. Chris Christie at 10 and former Arkansas Gov. Mike Huckabee at 8.

Sen. Lindsey Graham registers at only 1 percent support in his home state. Only 30 percent view him favorably against 53 percent who said they have a negative view of him.

“It’s difficult for Graham to argue there’s a rationale for his candidacy when his home state numbers are this poor,” Murray said.

The Monmouth University survey of 401 likely Republican primary voters was conducted between Nov. 5 and Nov. 8 and has a 4.9 percentage point margin of error.