Mitt Romney’s lead in Saturday’s South Carolina primary is eroding, but he’s still up by double digits, according to a new CNN/Time/Opinion Research poll.

The poll showed Romney’s 18-point lead from a week and a half ago declining to 10 percent.

He now leads Newt Gingrich 33 percent to 23 percent. Rick Santorum, who is competing with the former House speaker for the conservative anti-Romney mantle, is third at 16 percent, Rep. Ron Paul (Tex.) is fourth at 13 percent, and Texas Gov. Rick Perry is fifth at 6 percent.

Regardless of what happens in South Carolina, though, Romney looks strong in the next primary, Florida.

CNN also polled the Sunshine State, where Romney has a 24-point lead. He leads Santorum 43 percent to 19 percent, with Gingrich third at 18 percent, Paul fourth at 9 percent and Perry at 2 percent.

Florida’s primary follows 10 days after South Carolina’s, on Jan. 31. Romney’s campaign is so far the only one with a robust media presence in the state, where it is very expensive to run a campaign.

In South Carolina, much like in Iowa, Romney appears to be struggling with evangelical voters. The crosstabs show him winning 26 percent of self-described born-again Christians but 47 percent of everybody else.

He is also under-performing a bit among conservative voters.

But despite his struggles with those groups, Gingrich and Santorum are splitting the vote in both of them, and Romney still leads the field among both born-agains and conservatives.