Facing weakening support among the key constituent, the president expressed deep frustration Wednesday over what he called an inaccurate and damaging perception that he can address the polarizing problem without bipartisan support.
"This notion that somehow I can just change the laws unilaterally is just not true," Obama said during , a key constituency for the president's re-election campaign.
The president said comprehensive immigration reform continues to be a "top priority" for his administration. But he blamed Republicans in Congress for failing to join Democrats in supporting legislation that would address the flow of foreigners into the U.S. and deal with undocumented immigrants already in the U.S.
"Only a few years ago, as I said, you had some Republicans who were willing to recognize that we needed to fix our immigration system," Obama said, noting that his predecessor, George W. Bush, was among them. "Right now you do not have that kind of leadership coming from the Republican Party."
A strong majority of Hispanics supported Obama's election in 2008. But his support among Hispanics has declined, as it has in the broader population. A recent Gallup survey found 48 percent of Hispanic voters approving of Obama's job performance, compared with 60 percent in January.
While Obama has made little progress on comprehensive immigration legislation, he has pushed Congress to pass the Dream Act, which would provide a route to legal status for college students and service members brought to the country as children. The bill passed the House last year when it was controlled by Democrats but was blocked by Senate Republicans.
"I think there's been a great disservice done to the cause of getting a Dream Act passed and getting comprehensive immigration passed by perpetrating the notion that somehow by myself I can go and do these things," Obama said. "We have to pass bills through the legislature and then I can sign it."
Democrats view Hispanic voters as a voting bloc in 2012 that could help determine the outcome in swing states such as Florida, Colorado and Nevada. The Democratic National Committee has aired Spanish-language ads in those states in the past week to tout the benefits of Obama's jobs bill for small business and workers in the construction industry, which the DNC said employs 2.77 million Hispanics.
Hispanics accounted for more than half of the U.S. population increase over the last decade, exceeding estimates in most states and totaling 50 million.
The burgeoning Hispanic population, Obama said, means it will only be a matter of time before the country sees a strong Latino candidate for president or vice president.
"I am absolutely certain that within my lifetime we will have a Latino candidate for president who is very competitive and may win," Obama said.
The president spent more than 30 minutes taking questions submitted online, covering topics from U.S. policy toward Cuba to the president's $447 billion jobs bill. Obama said the jobs legislation would have a particularly positive impact on the Hispanic community, which has an unemployment rate of 11.3 percent, compared with the national unemployment rate of 9.1 percent.
Obama also said he believed federal courts would rule "fairly soon" on the Defense of Marriage Act, or DOMA, the law that defines marriage as between one man and one woman. While the White House backs repealing DOMA through Congress, Obama said Wednesday that he does not believe there are enough votes on Capitol Hill to overturn the law.
The president was also pressed on the status of Puerto Rico, where a statehood referendum is planned for next year. Obama said he believes the island will remain a U.S. commonwealth unless there is a "solid indication" of support for statehood.
"If it split down the middle or 51-49, I think Congress' inclination is going to be not to change but to maintain status quo until there is greater indication there is support for change," he said.
It's unclear whether any Republican presidential candidate can sway Hispanic voters. Several top GOP contenders, including former Massachusetts Gov. Mitt Romney, have taken a hard line on immigration, calling for a fence and more troops along the border with Mexico to stop the flow of undocumented immigrants.
Texas Gov. Rick Perry has been the outsider on immigration in the Republican field, and he is hoping his moderate record will appeal to Hispanics. But his rivals believe Perry's stance on immigration could be a weakness with his party's more conservative wing.
Perry insists that a physical border fence is an impractical way to control the flow of immigrants into the U.S. He also supported a 2001 Texas law that allows the children of undocumented immigrants to receive in-state tuition at Texas universities if they meet certain requirements.
Based on reporting by The Associated Press.