Hispanic voters could mean the difference between a victory and a loss for lawmakers in key states where Democrats are fighting for their political lives.
More Latinos today identify with the Democratic Party than a decade ago. In 2008, they voted overwhelmingly for candidate Barack Obama, who earned 67 percent of their votes compared to 31 percent for Sen. John McCain.
They turned out in record numbers in 2008, with more than 85 percent of all Latino registered voters going to the polls, according to the Pew Hispanic Center.
Democrats are hoping for a similar surge this year. In a nationwide survey conducted by Pew Hispanic Center, two-thirds, or 65 percent, of Latino registered voters said they plan to support the Democratic candidate in their local congressional district, while just 22 percent said they would support the Republican candidate.
That support could be crucial for Democrats in states with a large Hispanic population and where candidates are tied in tight political battles such as Arizona, California, Colorado, Florida, Illinois, Nevada and Texas.
The hot-button issue of immigration -- while not necessarily the top issue of concern among registered Hispanic voters -- still has alienated Hispanics from Republicans. From New York to Colorado, GOP candidates have come out forcefully against illegal immigration and amnesty.
"When there are commercials that show nefarious looking actors sneaking around a fence, it doesn't matter how acculturated you are. There is a little bit of a sting out of an ad like that," said Robert E. Lang, professor of sociology and director of Brookings Mountain West at University of Nevada, Las Vegas, referring to Nevada GOP candidate Sharron Angle's campaign ad. "Any time you say, 'This is the other,' and you push the other away from the core, you alienate them in that process."
But that doesn't mean Democrats are spared on that front. There's increased voter discontent about inaction from Democrats on the immigration front, a discontent that some groups have tried to exploit.
Overall, the excitement and momentum that grew in the Hispanic community in 2008 has waned, especially compared to other voting groups. Just one-third of all Latino registered voters say they have given this year's election "quite a lot" of thought, compared to half of all registered voters who say the same, according to Pew.
Compared to other registered voters, Latino voters are likely to be younger and less engaged in the political process, said Mark Lopez, associate director at the Pew Hispanic Center.
Lang said the momentum this year is with older white voters, many of whom relate to the Tea Party and support more conservative policies.
"For now, it [immigration] appears to be a bigger issue with white voters because they're fed up with it. It's an easy pointing finger ... this angst-filled moment for a lot of the white voters," Lang said. "The Democrats have not done an effective job of advertising well. They're vulnerable politically to charges" leveled by Republicans.
There are several House seats for play in Arizona, Texas and Florida where Hispanics could tip the balance, leading both parties to court them extensively.
ABC News took a closer look at those three states, where the battle for the Senate seats has reached new heights.