President Obama on Tuesday said the House has a “very narrow window” of two or three months to move forward on immigration reform. “The closer we get to midterm elections, the harder it will be to get things done,” Obama said during a meeting with more than 40 law enforcement officials Tuesday at the White House, according to a report from The Hill.  “Our broken immigration system makes it harder for our law enforcement agencies to do their job,” Obama said.

The meeting was the latest in a series of meetings between Obama and stakeholder groups as the White House tries to whip up support for immigration reform.  White House officials are hopeful they can pressure Speaker John Boehner (R-OH), who has voiced support for reform on the issue, to move on legislation approved last year by the Senate. But Speaker Boehner has said repeatedly that the House will not vote on the Senate bill. “Republicans are committed to reforming our immigration system, but as the speaker has said repeatedly, it’s difficult to see how we make progress until the American people have faith that President Obama will enforce the law as written,”  said Boehner spokesman Michael Steel.

Meanwhile, Senate Republicans say they will try to pass immigration reform legislation in the next two years if they take back the Senate in November.  The Republicans say winning back the Senate will allow them to pass a series of bills on their own terms that have a better chance of winning approval in the House, according to The Hill.

Senator Marco Rubio (R-FL), an important member of the coalition that passed a comprehensive reform bill in the Senate last year, said he would craft a better legislative approach if Republicans control the upper chamber in 2015.  That would give Republicans a chance to pass immigration legislation before the presidential election, when Hispanic voters will be crucial to winning the White House.

Senator Chuck Grassley (R-IA), who is poised to take over as chairman of the Judiciary Committee, said he will vote to pass immigration legislation in the next Congress if Republicans ascend to the majority.  “We’d start over again next year,” Grassley said, “I’d make a decision about whether you could get more done by separate bills or a comprehensive bill,” he said.

Those close to the debate believe that Senate Republicans feel confidant that House Republicans would be more likely to pass immigration reform if the midterm election shifts control of the upper chamber because it would be easier to negotiate a Senate-House compromise.

However, Senator Charles Schumer (D-NY), the lead author of the comprehensive Senate immigration bill, said this week that Democrats would not be willing to join in the effort to pass a variety of separate bills.  “I am saying that if Speaker Boehner, House Majority Leader Cantor, and other Republican leaders refuse to schedule a vote on immigration reform during this window, it will not pass until 2017 at the earliest,” he said on the Senate floor on Wednesday.  “I believe it would then pass in 2017 after Republicans take a shellacked in the Presidential election,” he said.

In the interim, the Department of Homeland Security is undertaking an internal review of how the White House might alter deportation procedures unilaterally. While the White House has insisted executive action will be no substitute for legislation, Homeland Security Secretary Jeh Johnson, who is spearheading the review, was among the administration officials at the meeting with law enforcement on Tuesday.

Immigration reform advocates have increasingly pushed for Obama to take executive action to slow or halt deportations in the absence of congressional action on a comprehensive proposal. And large cities have started to balk at requests from Immigration and Customs Enforcement as part of the Secure Communities program to delay the release of illegal immigrants for possible deportation proceedings.

Law enforcement advocates supportive of immigration reform say that giving legal status to illegal immigrants will keep cities safer by allowing people to come forward with reports of crime without fear of being deported themselves. And the federal detention policies, they argue, are taking up resources that would be better spent targeting violent crimes.