Obama to GOP: Stop moving goalposts on immigration reform

President Obama said Tuesday he has "gone above and beyond" Republican demands on border security and said those on the other side of the aisle should come to the table on comprehensive immigration reform.

In a major speech in El Paso, Texas, the president stepped headlong into the immigration fight, urging the audience to pressure Congress to take action despite seemingly long odds that such major legislation will pass heading into a presidential election year.

Making a case for comprehensive reform and passage of the Dream Act, Obama mocked Republicans who say they will not support reform until the borders are secured.

"Maybe they'll say we need a moat," Obama said. "Or alligators in the moat. They'll never be satisfied, and I understand that. That's politics."

Obama also addressed his critics on the left, such as Rep. Luis GutierrezLuis Vicente GutierrezDem tears into Kelly over immigrant comments: 'He eats the vegetables that they pick' WATCH: Gutiérrez says ‘lonely’ Trump can cry on KKK’s shoulder over WH departures Read Trump's remarks at Gridiron dinner MORE (D-Ill.), who want him to use his executive power as president to halt some deportations.

"I know some would wish that I could just bypass Congress and change the law myself," Obama said. "But that's not how democracy works. What we really need to do is keep up the fight to pass reform. That's the ultimate solution to this problem."

The president, acknowledging the hot-button nature of the issue, said "when an issue is this complex, when it raises such strong feelings, it's easier for politicians to defer the problem until after the next election."

"And there's always a next election," Obama said. "So we've seen a lot of blame and a lot of politics and a lot of ugly rhetoric around immigration."

The president said that since 2006, when former President George W. Bush and Sen. John McCainJohn Sidney McCainOvernight Defense: Pompeo lays out new Iran terms | Pentagon hints at more aggressive posture against Iran | House, Senate move on defense bill Senate GOP urges Trump administration to work closely with Congress on NAFTA Sarah Sanders: ‘Democrats are losing their war against women in the Trump administration’ MORE (R-Ariz.) were leading the charge for reform, Republicans have called only for increased border security.

Obama outlined steps his administration has taken to secure the border, including adding 20,000 agents, authorizing unmanned aerial drone flights over the border and completing the fence begun by Bush.

"So, we have gone above and beyond what was requested by the very Republicans who said they supported broader reform as long as we got serious about enforcement," Obama said. "But even though we’ve answered these concerns, I suspect there will be those who will try to move the goalposts one more time."

The president outlined what he considers the moral and economic imperatives of pushing for reform. And he acknowledged that demise of the Dream Act in the Senate last Congress — the legislation would provide a pathway to legal residency for the children of illegal immigrants — was "a tremendous disappointment.” He said lawmakers got “so close” only to see “politics get in the way."

Despite almost universal skepticism in Washington that reform can get done with Obama running for reelection, the president pledged Tuesday to do his "part to lead a constructive and civil debate on these issues."

"The question is whether those in Congress who previously walked away in the name of enforcement are now ready to come back to the table and finish the work we’ve started," Obama said.