Senate Republicans have introduced a group of amendments to the emergency supplemental spending bill all aimed at beefing up the U.S. border with Mexico, a bit of a legislative curve-ball for Democratic Leader Harry Reid, D-NV. The move held up floor activity for much of Wednesday.

Reid also hit another snag, as he tries to complete action on this bill by week's end, after which Congress goes on a week-long recess in observance of Memorial Day.  Sen. Russ Feingold, D-WI, has introduced an amendment that would require that the President set “a flexible timetable for the responsible draw down of U.S. troops from Afghanistan.”     A Senate Democratic aide tells Fox that Feingold will support a filibuster of the bill if the senator does not get a vote, but Reid did not sound like he was willing to hold such a vote.

The leader indicated at a news conference earlier that votes are possible on some of the GOP measures, and a spokesman for Senate Minority Leader Mitch McConnell, R-KY, confirmed that the votes are likely to happen later in the day.

In addition, the House is expected to approve a White House request for $500 million for border protection and law enforcement. It is unclear how the Senate will deal with that, as this figure does not appear in the Senate’s version of the spending bill.

It is also unclear where the votes stand for some of the GOP amendments, including adding 6,000 National Guardsmen to the border, building the rest of the 700-mile border fence, and implementing a program for strict treatment of illegals in the border sector.

Bolstering border enforcement and security measures often enjoys wide bipartisan support, but it’s possible the Democratic leadership could push its members to withhold support in favor of a more comprehensive approach they would like to try to take up later this year.

The supplemental contains a number of items popular to members on both sides of the aisle: $33.5 billion for ongoing operations in Iraq and Afghanistan; $5.1 billion for FEMA to deal with past disasters, like Hurricanes Katrina, Rita, and Ike, as well as Midwestern floods and California wildfires; $6.2 billion for the State Department, which includes aid for Haiti; and $13.4 billion in mandatory spending for Vietnam veterans affected by the defoliant Agent Orange.

Reid has moved to shut off debate on the bill, setting up a key test vote for Thursday. If he is able to round up 60 votes, which will require GOP support, the border security amendments and Feingold's effort would be erased from the slate, if they are not voted on prior to the test vote.

With the money for the troops embedded in the bill, some Republicans are likely find it exceedingly difficult to oppose the measure, particularly in this rough midterm election year where every move could set off a powder keg of condemnation from voters already disgusted with Washington.   And if an effort by Sen. Tom Coburn, R-OK, to pay for the bill fails, as is expected (though all Republicans are expected to support this), Republicans could feel free to vote for the bill.