Responding to the GOP base, the Republican Party and its leading presidential candidate, former Massachusetts Gov. Mitt Romney, may be unable to embrace comprehensive immigration reform and reject harsh right-wing, anti-immigrant rhetoric. So it’s difficult for Romney to make significant headway among this important part of the U.S. electorate. It may well tilt the playing field to Obama — who won two-thirds of the Latino vote in 2008.

I represented a large Latino population in Texas for the 26 years I served in the House. So I understand this important political struggle. Here are several lessons going forward.

First, though Romney captured the Cuban vote in the Florida primary, this doesn’t mean the GOP can win Latino votes this fall. Unlike other Latino voters, Cuban-Americans are reliably Republican.

The vast majority of Latinos in other states, however, are not from Cuba. Many are from Mexico, as well as Central America and Puerto Rico. Even in Florida, there is now a significant number of non-Cuban Latinos, who tend to vote Democratic.

Second, assuming Romney is the Republican nominee, he has a lot of ground to make up with Latinos after being pushed far to the right on the immigration issue during the early primaries and caucuses.

Many Latinos are culturally conservative, patriotic and remarkably entrepreneurial. On paper, this sounds like fertile territory for the GOP. But once Latinos have heard the GOP’s strong anti-immigrant rhetoric, they may well stop listening to anything else Republicans have to say.

Look at what’s happened so far.

Texas Gov. Rick Perry actually said some sensible things about immigration in an early debate. He spoke favorably of the DREAM Act, which permits illegal immigrant children to attend state colleges and pay in-state tuition. He condemned the proposed fence along the U.S.-Mexico border as a terrible idea.

Perry quickly had to backtrack when attacked by Romney and the GOP candidates, as well as influential conservative groups.

Former House Speaker Newt Gingrich, in another early debate, supported the framework of earned legalization — under which illegal immigrants who have lived in the U.S. for a long time, have families and jobs and have stayed out of criminal trouble, could apply for citizenship after going to the end of the line and paying a fine.

As soon as he was attacked by the far right for this sensible proposal, Gingrich had to do back flips to say he did not favor amnesty. He ultimately had to back away from this approach.

Meanwhile, the Republican Legislature in Texas, in a high-profile action, recently refused to create additional Hispanic congressional districts. It did this even though Latino communities accounted for most of the state’s population growth in the decade, which gained Texas four new districts. This matter is still in the federal courts, but it is being closely monitored by Hispanic groups, who filed lawsuits challenging the Legislature’s plan.

In addition, Arizona Gov. Jan Brewer continues to be a lightning rod for the most xenophobic, anti-immigrant sentiments in the Republican Party.

So despite a good showing among the Cuban community in Florida, the Republican presidential nominee starts in a deep hole with Latino voters nationally.

Can Republicans repair the damage?

Romney, for one, late in the Florida primary took a baby step on the subject of the DREAM Act. He said he would consider a path to citizenship for young Latino illegal immigrants now living in the U.S., who agree to serve in our military. He will probably have to move even further on this issue to win real support.

Romney will have to move off his hard-line position on immigration reform if he is to make a credible pitch to Latino voters. Building a fence and deporting 11 million people through “self-deportation” is not the answer. He may be considering moving toward Gingrich’s original position on earned legalization. But any change would need to be much more than baby steps to be credible.

The GOP must continue to showcase high-profile Republican officeholders, like Florida Sen. Marco Rubio and New Mexico Gov. Susana Martinez. However, putting people like Rubio on television as a spokesman won’t be enough if the party forces them into an ideological straitjacket on immigration reform.

Keep your eye on this important voting bloc. Right now, it’s advantage Obama.