As Congress grapples with the contentious issue of the treatment of terror detainees, Democrats have been more than happy to sit back and let Republicans fight among themselves.
Now Democrats hope the same dynamic may help them out on the equally divisive issue of border security.
The Senate is poised to take up a border security bill that would create 700 miles of fencing along the southwest border and mandate that the Department of Homeland Security maintain "operational control" over the entire border. The House passed the same measure, which has been dubbed the Secure Fence Act, last week.
Immigration reform has emerged as a potentially critical issue in the upcoming midterm elections, particularly among the Republican base. Many Republican lawmakers were deluged with mail from constituents over the summer, demanding that Congress take stronger action to secure the border. The business community, another key GOP constituency, has agitated for a more comprehensive approach to reform, including a guest worker program.
The House and Senate passed different immigration measures earlier in the year. The House measure dealt exclusively with border security and enforcement, while the Senate passed a broad overhaul measure favored by President Bush. But the two chambers have failed to reach a compromise.
Instead, the House is moving forward with a series of individual border security measures and will take up three more this week.
"I think we have strengthened our hand innumerably when it comes to our dealings with the Senate," House Majority Leader John Boehner told reporters.
And Senate Majority Leader Bill Frist is urging the Senate to follow the House's lead. "We've got to secure our borders," he said. Frist said he did not believe that passing the fence measure would doom the comprehensive reform bill the Senate passed earlier in the year but added "we need to start where there is general agreement."
Jim Manley, a spokesman for Minority Leader Harry Reid, called Frist's decision to bring the measure to the floor a "stunning repudiation" of the comprehensive approach favored by President Bush. "It smacks of desperation," he said, adding: "clearly, they're having problems with their base."
Reid indicated that Democrats will not try to block the bill from coming up but said he hoped there would be opportunities to amend it. Democrats are likely to try to attach the entire comprehensive reform bill as an amendment.
"We believe that border security is important, but it should be tied to other things," Reid said.
But if Democrats are not allowed to amend the measure, they will face a difficult choice. If they vote for it, they will lose whatever leverage they still have in trying to work out a compromise for a broader reform package with the House. If they vote against it, Republicans may be able to use the issue against them on the campaign trail.
Republicans who supported comprehensive reform -- such as Sen. John McCain of Arizona or Sen. Arlen Specter of Pennsylvania -- could give Democrats some cover to vote "no" if they vote against the measure as well.
On Tuesday Specter told reporters, "I am for the fence, but I am not for the fence piecemeal, which would preclude a comprehensive bill. I am not for that at all."
But Republicans face even greater pressure to vote in favor of border security than Democrats do, since it's an especially important issue for their base. Many of those same Republican lawmakers are already waging intraparty warfare over the issue of detainee treatment, and some may not be willing to exacerbate that split by adding immigration to the list.