The auto-industry crisis is forcing a broader debate over how far the government should go to prop up ailing industries, as the Bush administration resists Democrats' request to use part of the $700 billion financial-rescue fund to aid Detroit's three struggling car makers.

House Speaker Nancy Pelosi of California and Senate Majority Leader Harry Reid of Nevada, in a letter Saturday, formally requested that Treasury Secretary Henry Paulson consider giving "temporary assistance to the auto industry" using money originally appropriated...