You may think Donald Trump is a self-promoting clown who doesn’t have a chance to win the GOP’s presidential nomination.

But that’s because you’re not a Birther — unlike 42% of the Republican voters in New Hampshire.

Romney leads the first-in-the-nation primary contest in a multitude of scenarios involving difference candidates, often by as much as a 2-1 margin, according to a survey out Tuesday from Public Policy Polling. But when Trump gets into the race, Romney’s edge shrinks to 6 points, 27 percent to 21 percent.

If Trump isn’t included in the survey, Romney draws 32 percent of the vote, with Mike Huckabee a distant second at 15 percent.

The difference is the birthers: The Democratic polling shop found that Trump leads Romney among those who doubt President Barack Obama’s citizenship 22 percent to 21 percent. A previous PPP survey found that 42 percent of New Hampshire GOPers don’t believe Obama was born in America.