Barbosa had plenty of company. After making gains among Latino voters for three election cycles in a row, the GOP suffered a sobering reversal in this month’s midterm elections. Exit polls show that Republican candidates won only 30 percent of the Hispanic vote–the fastest-growing segment of the electorate–while Democrats garnered 69 percent. Compare that with 2004, when President George W. Bush captured at least 40 percent of that vote. While Latinos were just as concerned about Iraq and the economy as the electorate generally, according to surveys, they were more driven than usual by immigration. A poll by Lake Research Partners found that half of Latino voters considered immigration important to their vote this year. Many Hispanics were clearly turned off by GOP congressional candidates like Randy Graf in Arizona, who vilified illegal immigrants. “Those candidates got the spanking they needed,” says Lionel Sosa, Bush’s longtime Latino ad man. “We as a party got the spanking we needed.”

Reeling from the results, Bush quickly named a Hispanic, Sen. Mel Martinez, as the national party’s next general chairman. Martinez, who is hanging on to his Senate seat, has his work cut out for him. A president who has often promoted himself as simpático to Latinos now has worse approval ratings among them than among the public as a whole. The GOP’s hard-line voices especially alienated immigrant Latinos who only recently became citizens and have yet to form fixed party loyalties. Martinez must now refocus the GOP on the positive, aspirational message that once served Bush so well, says Al Cardenas, former head of the Florida Republican Party. It helps that Martinez is Latino; but as a Cuban-American from Florida, he won’t necessarily connect with, say, Mexican-Americans in the Southwest. And many conservatives decried his selection, citing his support for legalizing most undocumented immigrants. (Martinez declined repeated requests for an interview and hasn’t spoken much publicly about his appointment.)

But Democrats can’t assume that Latinos now form a pillar of their party’s base. “It could absolutely swing again next cycle,” says Cecilia Muñoz of the National Council of La Raza. “What this really reflects is a vote away from Republicans, which is not the same thing as a vote affirmatively for Democrats.” The Democrats face their own internal schisms over immigration. But Simon Rosenberg of the New Democrat Network argues that Hispanics will loom large in the party’s presidential nomination process for 2008: Latino-rich Nevada has moved up the primary calendar, and Hispanics like Gov. Bill Richardson of New Mexico will be highly visible.

Immigration will continue to shape the parties’ fates. Though lawmakers failed to strike a deal this year, they may take up the issue again next year, now that Democrats are in charge on Capitol Hill. A likely starting point: a compromise bill passed by the Senate that combines border enforcement with legalization of most undocumented immigrants. In the wake of the midterm elections, “demagoguery was soundly defeated,” says La Raza’s Muñoz. “But we have no illusions about immigration becoming an easy debate.” Voters like Barbosa in Illinois will be watching closely–and may well cast their vote accordingly come 2008.