The Republican base is being rejuvenated, some conservative activists say, by a flurry of congressional action on "values" issues such as marriage safeguards, flag protection and abortion restrictions, as well as President Bush's veto last week of stem-cell legislation. They warn against counteracting that progress with a comprehensive immigration bill that conservatives consider amnesty. Jim Backlin, vice president of legislative affairs at the Christian Coalition, said the spate of "values" votes "really, really helps rejuvenate our base -- especially Bush vetoing the stem-cell bill." In the past few months, Mr. Bush signed legislation against broadcast indecency, both chambers of Congress...