Supporters of immigration reform legislation are pointing to a March 21 rally on the National Mall as a target date for Members to release legislative language that could be marked up this year.

“They have a huge opportunity,” Ali Noorani, executive director of the National Immigration Forum, said of the March for America rally, which is expected to draw thousands of immigration reform supporters to the National Mall.

“On March 21, they can tell the country they’re committed to fixing this problem and this is their plan. Or, they can miss out on this opportunity,” he said.

The latest push comes as Sens. Charles Schumer (D-N.Y.) and Lindsey Graham (R-S.C.), who continue to hone a bipartisan outline on immigration reform, prepare to meet Monday afternoon with President Barack Obama on the subject. Obama pledged during his campaign to address the issue, and he reiterated his commitment in his State of the Union address.

Asked about the nature of Monday’s meeting, White House Deputy Press Secretary Bill Burton said, “It’s as simple as getting an update from them on efforts to create bipartisan immigration legislation.”

Schumer and Graham have worked for weeks to woo an additional Republican co-sponsor to join their negotiations, without success. Advocates are using the March 21 rally to apply pressure to the duo to introduce their bill without additional co-sponsors, hoping that additional Senators might sign on as the bill is marked up in committee and nears action on the Senate floor.

Additionally, advocates charge that immigration reform fits seamlessly with Congress’ jobs agenda and would be a helpful issue for Democrats to take up before the midterm elections.

“Our argument is that immigration reform is going to be what helps the economy,” said Frank Sharry, executive director of the immigration reform group America’s Voice. “It’s not going to solve the economy, but it’s going to create a fair economy at the low end of the labor market.”

Noorani and Sharry both signed on to a letter sent to Obama, Senate Majority Leader Harry Reid (D-Nev.) and Speaker Nancy Pelosi (D-Calif.) last week calling for the Senate to produce a bipartisan bill by March 21, with a markup in the Judiciary Committee by April 23.

“Through our national campaign of unprecedented size and scope, we are prepared to support your leadership on comprehensive immigration reform in 2010,” the letter read. “Our communities are coming to Washington in the tens of thousands on Sunday, March 21, 2010 to call on our leaders to enact comprehensive immigration reform now, and to underscore the fact that the people who voted for ‘change’ in 2008 expect action from their leaders.”