Romney, Obama tied in Colorado

New polls of likely voters in two battleground states released Thursday show President Barack Obama with a slight advantage in Nevada but tied with Republican challenger Mitt Romney in Colorado.

The NBC News/Wall Street Journal/Marist polls were conducted Tuesday and Wednesday -- entirely after Monday's third and final presidential debate. In Colorado, the race is tied at 48% for each candidate, while in Nevada voters split 50% for Obama and 47% for Romney.

The three point advantage for Obama is within the survey's sampling error of plus or minus three percentage points. An American Research Group poll of Nevada likely voters conducted both before and after Monday's debate found a similarly close race, with Obama at 49% and Romney at 47%.

The pollsters said their survey is evidence of a tightening race in Colorado, where Obama broke 50% in a mid-September poll, with Romney at 45%. That survey was conducted after the party conventions but before the debates.

Romney's favorability ratings have increased in both states since that September sample: in Colorado, he gained five points (from 43% to 48%) and in Nevada, he added three points (from 45% to 48%). Obama's favorability moved up two points in Nevada (from 50% to 52%) but remained at 51% in Colorado.

Following the third presidential debate's focus on foreign policy and national security, Obama retains an advantage on the subject. His edge over Romney was 51% to 44% in both states.

The polls were conducted October 23 and 24 by telephone. The Nevada sample included 1,042 likely voters and has a sampling error of plus or minus three points. In Colorado, 1,128 likely voters were contacted, and the poll has a sampling error of plus or minus 2.9 percentage points.