Dancers from Ballet Folklorico Mexicano de Georgetown perform at a Cinco de Mayo reception at the White House in Washington, May 3, 2012. REUTERS

Seeking to reassure a Hispanic constituency that has grown disillusioned with some of his policies, President Obama reiterated his support for the DREAM Act during a Cinco de Mayo address, and blamed Republicans for obstructing immigration reform.

The DREAM Act -- a thwarted piece of legislation that would grant citizenship to some undocumented immigrants who arrived in the country as young children, have clean criminal records and have pursued college or military service -- has become a partisan litmus test in the debate over immigration reform. The bill is heavily supported by Democrats and Latino advocates, but Republicans oppose it on the grounds that is represents amnesty for law breakers.

We're going to keep fighting for this common-sense reform - not just because hundreds of thousands of talented young students depend on it, but because ultimately America depends on it, Obama said at a White House Cinco de Mayo reception . 'No' is not an option. I want to sign the DREAM Act into law. I've got the pens all ready.

The DREAM Act passed the House of Representatives in 2010 but Died in the Senate, where Republican senators denied the bill enough support to overcome a filibuster threat and get to a floor vote. Obama emphasized that Republicans are responsible for the bill failing, and said that he is prepared to work on a broad overhaul of the nation's immigration laws, implying that he has been unable to do so because Republicans have not joined him.

I'm willing to work with anybody who is serious to get this done, and to achieve bipartisan, comprehensive immigration reform that solves this challenge once and for all, Obama said at the reception.

Mitt Romney said he would veto the DREAM Act but has since softened his stance somewhat, acknowledging to supporters that the GOP's anemic approval rating among Latinos could be a key vulnerability and floating the idea of an alternate DREAM Act. Florida Sen. Marco Rubio, who is often mentioned as a top vice presidential pick, has been working on a substitute DREAM Act but has not yet formally introduced legislation.

Obama has frustrated Latino supporters by presiding over a record number of deportations -- about 400,000 a year so far -- while embracing enforcement mechanisms first implemented by President George W. Bush. There are signs that immigration will figure into the general election -- the Obama campaign released a Spanish ad blitz and has signaled its intention to paint Romney as extreme on immigration.

But the Thursday night reception provided a distraction from politics, with guests enjoying a traditional Mexican dance performance and margaritas.

We just like to get the fiesta started early around here, Obama joked in reference to the fact that the reception was held on the 3rd, not the 5th, of May.