WASHINGTON - The Senate rejected a call for the withdrawal of U.S. combat forces from Iraq by year's end on Thursday as Congress erupted in impassioned, election-year debate over a conflict that now has claimed the lives of 2,500 American troops. The vote was 93-6 to shelve the proposal, which would have allowed "only forces that are critical to completing the mission of standing up Iraqi security forces" to remain in 2007. The vote came alongside a daylong debate in the House, where Republicans defended the war as key to winning the global struggle against terrorism while Democrats excoriated President...