President Obama cast the new immigration bill as a law enforcement issue Tuesday, and told supporters they have only a "narrow window" of two or three months to get something through Congress before election season hits full force.
"The closer we get to mid-term elections the harder it will be to get things done," Obama told a group of law enforcement officials gathered at the White House complex.
Congressional elections are Nov. 4.
Obama noted that the Democratic-run Senate approved an immigration bill last year, but the Republican-run House has not taken action.
A revamped immigration system will also be good for law enforcement, Obama told his guests, making it easier for officers to stop criminals from crossing the border or exploiting a vulnerable labor supply.
The status quo "makes it harder for our law enforcement agencies to do their job," Obama said.
House Speaker John Boehner, R-Ohio, and other Republicans say they want to improve the immigration system, but don't trust the Obama administration to crack down on entries by undocumented workers.
"We have a broken immigration system, but it is impossible to make progress until the American people -- and their elected representatives -- have faith that the president himself will actually enforce the law as written," said Boehner spokesman Michael Steel.
Many Republicans also oppose a key feature of the Senate bill, a path to citizenship for people who are already in the United States illegally.