Proponents of a broad immigration measure narrowly beat back potentially fatal challenges Thursday, including an effort to phase out the temporary worker program.

The Senate rejected, 49-48, a proposal by Sen. Byron Dorgan, D-N.D., to end the temporary worker program after five years. Earlier, by the same margin, senators voted down a proposal by Sen. Norm Coleman, R-Minn., to allow government authorities to question someone about his immigration status if they had probable cause to suspect the person was in the U.S. illegally.