The U.S. Senate is to vote later Thursday, on an immigration reform bill that would toughen border security and give millions of illegals a chance to become American citizens.
On Wednesday, the Senate voted to limit debate on the controversial legislation.
Two other provisions in the bill would create a so-called guest worker program and would deport illegal immigrants who have been in the country for fewer than five years.
If the Senate passes the legislation, it will have to be reconciled with a bill passed by the House of Representatives last December. That bill emphasized border security and would make it a felony to be in the United States illegally.
The issue has sparked widespread demonstrations across the United States.