Despite White House assertions that the Senate is on track to pass the immigration bill this week, the fate of the measure is uncertain as possible amendments threaten to erode essential support.
On Tuesday, Senators voted 64-35 to resurrect the bill that had stalled earlier this month, but they have yet to consider 26 amendments that could prove to be stumbling blocks for Democrats and conservative Republicans.
One amendment being proposed by Sen. Kay Bailey Hutchison (R-TX) would require all 12 million undocumented immigrants in the U.S. to return to their native countries to apply for temporary visas. Originally, the bill required only those who were seeking permanent U.S. residency to return to their home countries.
If the Hutchison amendment is approved, the bill would likely lose some Democratic support.
Conversely, a Democratic amendment giving family ties more weight when a person is being considered for a visa would likely diminish support from Republican senators. The bill currently gives heavier consideration to an immigrant with advanced job skills and education.
Immigration reform has become a key tenet of President Bush's domestic policy. The White House worked with key Congressional leaders to come up with the compromise bill, which provides a path to citizenship for undocumented workers and tightens border security.
The bill's opponents have noted that they only need to persuade a handful of supporters to switch sides, and the measure will be a dead issue.
The next major vote is scheduled for Thursday.
From NPR reports and The Associated Press.