MIAMI, Sept. 20, 2012 -- President Obama appealed to Latino voters for a second term at a Univision-sponsored event today, and blamed Republicans for his failure to make good on his 2008 promise of immigration reform.

Univision news anchors Jorge Ramos and Maria Elena Salinas repeatedly grilled Obama over whether he broke his promise to bring up an immigration reform bill in his first year in office, which he made to Ramos in 2008.

"My biggest failure is that we haven't gotten comprehensive immigration reform done … but it's not for lacking of trying or desire," Obama said during the event at the BankUnited Center Field House on the University of Miami campus.

"I haven't gotten everything done that I want to get done," Obama added. "That's why I'm running for a second term."

The president said that his first years in office was consumed with attempting to rescue the collapsing economy through his stimulus and auto bailout, leaving little time to address a sweeping comprehensive immigration overhaul.

"That was before the economy was on the verge of collapse," Obama said of his "promise" to Ramos.

The president said that he was also taken aback by the resistance he said he received from Republican lawmakers when he reached out to them about an immigration bill, especially from those who previously supported such measures.

"I am happy to take responsibility for being naive here," he said.

Obama also contrasted his support for a pathway to citizenship for undocumented immigrants to that of Romney, whom he said is "uncertain about what his plan for immigration reform would be" beyond encouraging the undocumented population to "self-deport."

But Ramos would not let him off the hook. "A promise is a promise, and with all due respect, you didn't keep that promise," Ramos said, breaking from asking questions in Spanish to address the president in English.

The president enjoys wide lead among Latino voters over Republican Mitt Romney, who appeared at a similar Univision event Wednesday. But Obama faces a community that is not as enthusiastic about him as they were four years ago.

Obama's 2008 victory was partly fueled by a surge in Latino turnout and the fact that they voted for him over Republican John McCain by a two-to-one margin.

Obama holds an even wider lead over Romney this time around, but a Latino Decisions weekly tracking poll last week showed that Latino voters are no more enthusiastic about voting in November than they were before the party conventions. The president needs these voters to show up in November to better his chances of victory.

One of the main hangups for Latino voters has been the deadlock on an immigration bill as well as the high number of deportations under his administration. Around 1.4 million undocumented immigrants have been deported under the Obama administration as of July, the vast majority being Latino. By comparison, the Bush administration deported 2 million over the course of eight years.

Obama said that he has directed the Department of Homeland Security to focus on deporting criminal immigrants who are in the country illegally and not otherwise-law abiding ones who have families here.

He also touted his "deferred action" program that made over 1 million young undocumented immigrants eligible for a two-year reprieve from potential deportation.

"I met young people all across the country, wonderful kids who sometimes were valedictorians, were participating in the community, had aspirations to go to college, some were serving in our military," he said. "There's no way you would think it was fair or just for us to have them suffering under a cloud of deportation."

But when pressed by Salinas whether the timing of that announcement in June was made for political reasons, Obama suggested it was not prompted by the looming election. "I was winning the Latino vote before we took that action," he said.

President Obama Blames Republicans for Failure to Reform Immigration

The president also said the "the most important lesson" he has learned as president is that "you can't change Washington from the inside. You can only change it from the outside."

"That's how I got elected and that's how the big accomplishments like healthcare got done... because we mobilized the American people to speak out," he said. "Something that I would really like to concentrate on in my second term is being in a much more constant conversation with the American people so that they can help [convince] Congress to move some of these issues forward."

Obama presented himself as a committed friend of the Latino community on issues like immigration and maintaining funding for education programs. He contrasted his positions with Romney's and attacked the GOP candidate for being out of touch with average Americans, Latinos included.

The president laid into Romney for his comment that 47 percent of Americans don't pay income taxes and are dependent on the government, saying they showed Romney doesn't understand that people of lesser means want to better themselves.

"Maybe you haven't gotten around a lot," Obama said of Romney. "Americans work hard, and if they're not working right now, I promise you they want to get back to work."

But Obama could not avoid the grilling over a broad number of items in his record. Ramos and Salinas pressed him on whether he should fire Attorney General Eric Holder over the botched "Fast and Furious" gun-walking operation that allowed 2,000 guns to fall into the hands of Mexican drug cartels.

Obama called the operation "wrong-headed" and claimed that Holder stopped it once he caught wind of it. He also a defended an internal Justice Department investigation that cleared Holder, despite calls for an independent probe.

"Eric Holder has my complete confidence," he said.

Despite the gripes Latinos might have about Obama's first term, especially on immigration, the president argued that the best hope for a breakthrough is voting for him again.

"We still have more work to do," he said.