With House action now on hold until September at earliest, immigration bill backers see Congress' monthlong August recess as crucial to their cause. They're making plans to try to ensure that supporters of an immigration overhaul are heard as loudly as opponents when lawmakers return to their districts for town hall meetings and other events.

"Here's the fact: We're not winning, so we've got to wage a campaign," Sen. John McCain, R-Ariz., said Thursday. "There are many members of the House that don't want to take up any bill at all, as you know. What our job is, we want to convince them to at least pass legislation, so that we can go to conference and work together."

Immigration legislation, a top priority for President Barack Obama, has been in limbo since the Senate last month passed a sweeping bill with provisions aimed at securing the border, requiring employers to verify their workers' legal status, allowing many more workers into the country legally, and offering eventual citizenship to the 11 million immigrants already in the country illegally.