President Obama said Thursday night that he would take executive action on immigration sometime between the midterm elections and the end of the year.

Speaking before the Congressional Hispanic Caucus Institute Gala, Obama said he shares the frustration of many in the room upset that immigration reform remains stalled. Obama was accompanied to the gala by two congressional interns who are DREAMers -- young unauthorized immigrants who entered the United States before the age of 16.

"But if anybody wants to know where my heart is or whether I want to have this fight, let me put those questions to rest right now.  I am not going to give up this fight until it gets done," Obama said. "I know the pain of families torn apart because we live with a system that’s broken."

Obama laid blame squarely at the feet of congressional Republicans, who he said exploited a crisis of undocumented children at the southern border for political gain this summer and refuse to act with the president on immigration reform. However, he said, he ultimately needs Congress to pass an immigration law, because anything he does by executive action can be reversed by the next president.

"So the point I want to make is the progress we’ve made has been hard, sometimes it's been slower than we want, but that progress has been steady and it has been real," he said. "I want to make something clear:  Fixing our broken immigration system is one more, big thing that we have to do and that we will do."

Now, Obama said, he will also use immigration as a political tool -- by explaining immigration reform is a boon for the economy.

"And when opponents are out there saying who knows what, I'm going to need you to have my back," he said. 

Part of that, Obama said, is getting out in November and voting. Only 48 percent of voters turned out to vote in 2012, he said.

"So the clearest path to change is to change that number.  Si, se puede … si votamos.  Yes we can … if we vote.," he said.

And Obama said he needs them to continue to believe in him.

"And six years ago, I asked you to believe.  And tonight, I ask you to keep believing -- not just in my ability to bring about change, but in your ability to bring about change," he said.