Romney takes 48 percent support in Ohio, edging President Obama at 47, in the new poll conducted by American Research Group (ARG). It’s the latest survey to show Romney erasing the gender gap. He now trails Obama only 48 to 45 among female voters in the Buckeye State.

Obama had opened up a commanding lead in Ohio, which no Republican presidential candidate has lost in a successful bid for president. Before last week’s debate, some polls showed Obama with as big as a 10-point lead.

Obama now leads by 3, according to the Real Clear Politics average of polls.

Ohio is the third-largest swing state prize with 18 Electoral College votes at stake.

And in Colorado, likely voters went for Romney 50 to 46 over Obama, in ARG's poll. Romney soundly outpaced Obama among female voters in the state, taking 51 percent support against Obama at 45.

Obama led by 3 in Colorado heading into last week’s debate at the University of Denver, according to the Real Clear Politics average of polls. The candidates are now locked at 47, according to the RCP average.

Ohio and Colorado are two of the 12 states President Bush won in 2004 that Obama took in 2008. These 12 battleground states will be critical in determining the outcome of the 2012 election.

Obama had held a considerable lead in many swing states throughout the election cycle, but like the national polls, these states have tightened significantly since the debate.