Two states Colorado and Nevada are widely seen as swing states. Arizona is leaning toward Romney and New Mexico appears reasonably safe for President Barack Obama, according to polling data.
As the GOP presidential nominee in 2008, McCain won 31 percent of the Latino vote, losing the demographic by more than 2-to-1 to Obama, who snagged 67 percent, according to the Pew Hispanic Center.
Romney is faring even worse than McCain, according to a poll released last month by NBC News, The Wall Street Journal and Telemundo. That survey found Obama leading Romney 67 percent to 23 percent among Latinos. And there could be substantially more Hispanic voters in key Western states this year than there were in 2008.
An analysis by Matt Barreto, a political scientist and pollster with Latino Decisions, estimated that the percentage of Latino registered voters is in double digits in the key states surrounding Utah 12.1 percent in Colorado, 13.7 percent in Nevada, 18.4 percent in Arizona and a whopping 38.7 percent in New Mexico.
At the same time, nearly half the Latino adults in Colorado are not registered to vote.
Mannie Rodriguez, chairman of the Colorado Democratic Party's Latino Initiative, said campaigns like his have been working to change that, with registration drives at soccer matches, football games and other events around the state.
Rodriguez said he has seen enthusiastic support for Obama, especially among young people who he added are working hard to round up supporters. A few weeks ago, he said, his volunteers registered 10,000 voters in one weekend.
"If [Obama] picks up 70 percent or more [of the Latino vote], he will win Colorado," Rodriguez said.
Democratic Sen. Michael Bennet won 82 percent of the vote in squeaking out a narrow victory. "That's what it may take this election," Rodriguez noted, "because this is a conservative state, so it really is up to the Latinos and the women."
Republicans have attempted their own outreach efforts to Latinos, but David Damore, a political scientist at the University of Nevada-Las Vegas, said that it seems to be little more than "lip service."
"It really boils down to just picking off a couple of constituencies, so, for example, in Nevada, they'll spend a lot of time talking to Latino business owners," he said. Groups have also focused on social issues such as gay marriage.
"In terms of full engagement and discussion," Damore said, "you just don't really see it, and a large part of it is just because [Republicans] have put themselves in such a box on some of those issues [like immigration] with Latinos."
Damore believes Romney will do worse among Latinos than McCain, probably losing New Mexico and Nevada, as well. Colorado could remain close, but he expects the Latino vote will be significant in each state.
A defeat could serve as a wake-up call for Republicans, but winning over Latinos presents a difficult policy issue.
"It's hard to get those voters back without losing their base, who are hostile to anything other than enforcement-only immigration," Damore said.
McCain contends the GOP has some "impressive" young Latino leaders, citing Florida's Marco Rubio.
"It's a shame that the Republican Party that is pro-small-business, less regulation, lower taxes, very patriotic, pro-life, isn't doing better with the Hispanic community, because we share so many aspects of how the country should work with our Hispanic and Latino community," McCain said. "And obviously the reason for that is the issue of immigration."