The Post's Dan Balz and Jon Cohen report on a narrowly divided 2012 electorate with few remaining undecided voters:

Likely voters in the new poll split 49 percent for Obama to 46 percent for Romney, basically unmoved from the poll two weeks ago, just before the two candidates met in Denver for their first debate. On topic after topic, the survey portrays an electorate that remains deeply divided along partisan lines and locked in its views.

Nearly two-thirds say they do not need any more information before Election Day, and barely one in eight is undecided or says there is a chance he could change his vote. Even as voters overwhelmingly perceive that Romney won the first debate, the vast majority say their opinion of the president did not shift as a result.

But more people changed their views of Romney, largely in a positive direction. Overall, more than twice as many say their opinions of the former Massachusetts governor improved than say they worsened as a result of the debate. The strongest reaction is among Romney backers, 70 percent of whom say Denver made them think more highly of the GOP nominee.