A group of Republican moderates stuck with Democratic lawmakers yesterday and submitted bills in the U.S. House and Senate to cap carbon dioxide emissions from power plants, only two days after President Bush broke a campaign promise and said he wouldn’t support such legislation. Sens. Susan Collins (R-Me.) and James Jeffords (R-Vt.) and Rep. Sherwood Boehlert (R-NY) cosponsored the bills, which would also place limits on emissions of sulfur dioxide, nitrogen oxides, and mercury. When Bush went back on his promise, he expressed concern that energy costs could skyrocket if power plants were required to drop their CO2 emissions. Boehlert said that Bush “took the right stand” during the campaign last September and that “none of the information” cited as reasons for the president’s reversal on Tuesday was unknown last fall.