AMHERST, N.H. — The Republican presidential contenders are tying themselves in knots over immigration.

Newt Gingrich is endorsing a South Carolina law that allows police to demand a person’s immigration status — a week after taking heat for advocating a “humane” approach. Rick Perry, though defending Texas’ in-state tuition for some illegal immigrants’ kids, spent Tuesday campaigning with a hardline Arizona sheriff in New Hampshire. And Mitt Romney is talking tough on immigration in his second White House campaign, though he previously supported the idea of allowing some illegal immigrants to stay in the U.S.

Meanwhile, many voters say immigration won’t determine which candidate they’ll back for the GOP nomination. Instead, they say they’re focused squarely on the economy and jobs.

The contortions by the Republican candidates illustrate the straddle they’re attempting on a complex issue. In order to win the Republican nomination, they must court a GOP electorate that is largely against anything that could be called “amnesty” for illegal immigrants. But they can’t come off as anti-immigrant, a stance that could alienate the independents and moderates — not to mention Hispanics — they’d need to attract in a general election should they win the party’s nod to challenge President Barack Obama.

Enjoying a rise in national and state polls, Newt Gingrich called in a debate last week for an approach that would grant legal status to illegal immigrants with longstanding family and community ties. Since then, he has been defending that approach from attacks by opponents who say it would amount to amnesty for millions.

“What is it that you’re going to do? Are you really going to go in and advocate ripping people out of their families?” he said.

In New Hampshire, Perry looked to regain his footing on the issue that his dogged his campaign from the outset.

With Arizona Sheriff Joe Arpaio at his side, the Texas governor, who opposes a border fence with Mexico, defended anew his signing of legislation to allow in-state tuition for children of illegal immigrants.

“They are working toward getting citizenship, and they pay full in-state tuition,” Perry said. “As the sheriff knows, I’ve been fighting this illegal immigration issue for a decade. But the people of Texas made that decision.”

And yet, all that shifting by all those candidates may not matter to the bulk of conservative Republican voters in Iowa, New Hampshire and South Carolina, when the three states kick off the state-by-state march to the GOP nomination.

In interviews, several Republicans said that while the GOP nominee must be tough on sealing the border, they’ll choose the Republican who can best fix the economy, create jobs and beat Obama.

Printed on Wednesday, November 30, 2011 as: GOP candidates try tough immigration policy to court voters