In late September 2011, Rick Perry was riding high. Just a month and a half after joining the race for the Republican presidential nomination, polls showed the Texas governor leading the field by a wide margin. And it wasn’t just one poll:  Perry was in the midst of a six-week stretch in which he led every public poll conducted by a media organization.

But then his opponents started scrutinizing his record on illegal immigration — and a seemingly innocuous bill Perry had signed a decade before. That measure, a federal version of which supporters dubbed the DREAM Act, allowed undocumented immigrants who came to Texas as children to pay in-state tuition to attend college.

“The American way is not to give taxpayer-subsidized benefits to people who have broken our laws and are here in the United States illegally,” Rep. Michele Bachmann (R-Minn.) said at a Sept. 12, 2011, debate in Tampa, Fla. “Of course we do not give in-state tuition credits to people who come here illegally,” former Massachusetts Gov. Mitt Romney chimed in.

A week and a half later, at another Republican debate, this one in Orlando, Perry fought back: “If you say that we should not educate children who have come into our state for no other reason than they have been brought there by no fault of their own, I don’t think you have a heart,” he said.

It was the beginning of the end for Perry’s campaign. The Texas governor led one more poll — a CNN/Opinion Research survey conducted September 23-25 — and then began an epic downward spiral. By the time he forgot the name of the third Cabinet department he would cut, at a debate on Nov. 9 (“Oops”), national polls showed him lagging in the single digits.

Perry’s collapse demonstrated the potency of illegal immigration within the Republican Party. Even with House Republican leadership and conservative favorites like Florida Sen. Marco Rubio (R) on board, immigration hard-liners in the House have succeeded in blocking the bipartisan Senate immigration reform bill (Notably, the two other Republican senators contemplating presidential campaigns, Rand Paul of Kentucky and Ted Cruz of Texas, voted against the Senate bill).

While Republican candidates can survive other breaks from party orthodoxy — whether it’s John McCain on campaign finance reform or Mitt Romney on health care with an individual mandate — immigration remains a third rail.

Perry’s fate, and the death of immigration reform in Congress, makes New Jersey Gov. Chris Christie’s (R) decision to sign a bill similar to the Texas version all the more interesting.

Far from running from the issue, Christie is embracing the new law, and the changes he inspired. Though he signed it in private today, Christie will hold a public signing ceremony at a later date, his press office said.

The measure’s fate was no sure thing. Until Thursday, Christie maintained that he would veto the legislation without key alterations. Christie issued a conditional veto of the state legislature’s version of the bill, removing a section that would have made students eligible for state-funded financial aid programs like tuition grants; the legislature quickly voted again to pass Christie’s version.

“This is what compromise looks like. Sometimes it’s quiet. Sometimes it’s loud,” Christie said in a news conference on Thursday, according to the Newark Star-Ledger.

Christie said during his reelection bid this year that he supported allowing in-state tuition for so-called DREAMers, the children of undocumented immigrants who graduated from New Jersey high schools. And for Republicans desperate to do better among Hispanic voters, Christie stands out: He received 51 percent of the Hispanic vote, according to exit polls conducted on Election Day, compared with 45 percent for his Democratic opponent.

Public polling suggests that even Republican voters are taking a more conciliatory view on undocumented immigrants since Perry’s run for office. In a November survey conducted by Quinnipiac University, 44 percent of Republican voters said illegal immigrants currently living in the U.S. should be allowed to stay, and to eventually apply for citizenship. Another 15 percent said those immigrants should be allowed to stay, but without applying for citizenship. And just 38 percent of Republicans said those immigrants should be required to leave the U.S.

Still, should Christie decide to run for president in 2016, his rivals will likely make a point to bring up the legislation he signed Friday. He has to hope that the polling is accurate, that his party’s primary electorate isn’t dominated by immigration hardliners — or that Rubio, the only other potential 2016 candidate to stick his neck out on such a hot-button issue, takes the bulk of the incoming fire.