WASHINGTON — Republican challenger Mitt Romney narrowed the gap with President Barack Obama among likely voters in several swing-state polls released Tuesday.

Obama had a sizable lead in Ohio and one Virginia poll, while another survey in Virginia and those in Colorado, Florida and Wisconsin showed three points or less separating the candidates. According to strategists in both parties, these are among the states that — because of their history of voting for either major political party — will decide who wins the White House on Nov. 6.

A CBS News/New York Times/Quinnipiac University poll put Romney ahead in Colorado, 48 percent to 47 percent, a reversal of Obama's one-point lead last month. The president continued to lead in Virginia, 51 percent to 46 percent, up one point from his 50 percent to 46 percent advantage in September, and in Wisconsin, 50 percent to 47 percent, down from 51 percent to 45 percent the month before.