A new Bloomberg poll of South Carolina shows Donald Trump maintaining a strong lead in the state heading into Saturday’s primary.

Trump has the support of 36 percent of likely Republican voters, followed distantly by Ted Cruz in second with 17 percent support.

Marco Rubio, with 15 percent support, is in third, followed closely by Jeb Bush with 13 percent. Ben Carson has 9 percent, while John Kasich has 7 percent.

The poll, conducted by Iowa’s Ann Selzer, was conducted after the GOP debate last Saturday. The poll doesn’t show any drop in support for Trump following his criticism of former President George W. Bush over the Iraq War.

A slight majority of voters say their minds are made up on which candidate to support, while 43 percent say they could still change their minds. Supporters of both Trump and Cruz, however, are more strongly committed.

Among Cruz supporters, 68 percent say their mind is definitely made up. Among Trump supporters, a similar 63 percent say their mind is made up.

Trump may be benefiting from his tough rhetoric on trade and proposals to impose tariffs on goods imported into the U.S. Only 20 percent of likely Republican voters believe trade deals like the Trans Pacific Partnership help the U.S. economy. A massive 70 percent of voters would support import tariffs and duties on goods manufactured overseas.

A strong dose of caution on this poll is warranted, however, because of its sample make-up. According to this poll, the largest single block of likely voters, 39 percent, describe themselves as “mainstream Republicans,” while only a third, 33 percent, describe themselves as evangelicals. Another 20 percent describe themselves at “Tea Party Republicans.”

In both 2012 and 2008, evangelicals made up more than 60 percent of the Republican primary electorate. One reason the final Bloomberg poll in Iowa was so off was that it significantly undercounted the number of evangelicals in the state. That poll also identified “mainstream Republicans” as the largest likely voting block in Iowa.

In both the Iowa poll and the recent South Carolina poll, Bloomberg has Trump running very strong with “mainstream” Republicans. In both polls, in fact, it is his strongest ideological block of voters.

It is unclear how Bloomberg defines “mainstream” Republican voters. It is clear, however, that they were not the largest block of voters in Iowa. They are unlikley to be the largest block of voters in South Carolina either.

The Bloomberg poll, even with this caveat, does reveal a very interesting piece of information. If, as it expects, “mainstream” Republicans make up the largest block of voters, dwarfing evangelicals and Tea Party supporters, then candidates like Bush, Rubio, and Kasich are in for even more of a struggle than anyone realizes.

If these three are still struggling to gain traction with such a favorable electorate, then they really are candidates and campaigns in search of supporters.