Now the Obama campaign has a powerful case to make when it paints a picture for Latinos about what life under a Republican administration could look like.
The most recent USA Today/Gallup poll shows that Obama has already opened up a wide gulf among Latino voters, leading Republican Mitt Romney by 66 percent to 25 percent and putting Romney in the weakest position with Latinos since Bob Dole in 1996.
But the greater consequence of the Supreme Court's SB 1070 decision may be mobilization among the Latino community. As their numbers have grown, Latinos have indeed wielded more influence, usually to the benefit of Democrats.
Even so, their power has been muted by traditionally tepid participation compared with other groups. About 21 million Latinos will be eligible to vote in November, but only 10 million are registered. If past serves as precedent, even fewer will vote.
"The big question is turnout," said GOP strategist Ana Navarro, who advised 2008 Republican nomineeJohn McCain on Latino issues. "Between [Obama's] Dream policy announcement 10 days ago and this Supreme Court decision, what was a very disillusioned and lethargic base until a couple of weeks ago is now energized."
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That has the potential to make a difference in a number of swing states in the Southwest — Nevada, Colorado, and New Mexico — where the Latino population has skyrocketed over the past decade. Political analysts have also turned their attention recently to Arizona, a traditionally Republican stronghold that nevertheless has seen a sizable increase in its Latino population and where "show me your papers" actually will be felt. The Obama campaign recently began an aggressive registration effort there.
"I've seen polling in the last few weeks coming out of Arizona that show it within the margin of error, which is shocking and would be a real cause of concern for Republicans," Segura said. "If Democrats can make Arizona competitive, that will be a direct consequence of this law."
Nevertheless, Arizona-based political analyst Mike O'Neil points out that the Latino vote has been oft-promised and never delivered; 2012 would be a first if Hispanics do turn out in force.
"When you've got yourself or your neighbors pulled over on the street to be checked for papers "¦ I think [that] becomes potentially the grist for mobilization," O'Neil said. "Underscore is on the word potential. They still have to beat the pavements and make it happen."
The Arizona decision is the second time in two weeks that questions over immigration policy have put Romney in an awkward position. The former Massachusetts governor has been boxed in by his party's positions on the issue, even as many in the GOP have emphasized the importance of making inroads with Hispanic voters, who are wielding more power at the ballot box with each passing election cycle.