Disaffection over spending and immigration have caused conservatives to take flight from President Bush and the Republican Congress at a rapid pace in recent weeks, sending Bush's approval ratings to record lows and presenting a new threat to the GOP's 12-year reign on Capitol Hill, according to White House officials, lawmakers and new polling data. Bush and Congress have suffered a decline in support from almost every part of the conservative coalition over the past year, a trend that has accelerated with alarming implications for Bush's governing strategy. The Gallup polling organization recorded a 13-percentage-point drop in Republican support for...