President Obama has lost 64 electoral votes in the last 12 days, a new RealClearPolitics (RCP) Electoral College map, based on poll averages, showed on Thursday. According to the map, Obama now leads Romney 201-181, with 156 electoral votes up for grabs.

RCP moved five states from a “leans Obama” status to “toss-up,” causing the loss of votes in the president’s column. The moves were made following Republican challenger Mitt Romney’s post-presidential debate surge in multiple state polls, as his standing improved among voters nationwide. The five states that were moved to the “toss-up” category are Michigan, New Hampshire, Pennsylvania, Wisconsin and Ohio, bringing the total number of “toss-up” states to 12. The other seven are Virginia, Florida, Colorado, Iowa, Nevada, Missouri, and North Carolina.

A CBS local television station reported Wednesday that Obama had lost eight points in California, though the Democrat still leads there by a comfortable 53-39% margin (10 points fewer than when he won the state by 24 points in 2008). KPIX 5 TV’s tracking poll had the president leading Romney by 22 points four weeks ago. Among independents, the poll found Obama had lost 23 points, now down by 9, having led by 14 in September. The KPIX poll was carried out by SurveyUSA on October 7-9 and interviewed 539 likely California voters, with a margin of error of +/-3.9-4.3%.

IBD/TIPP polling carried out after last week’s presidential debate and published Wednesday found Romney’s lead among independent voters grew from 18 points on Tuesday to 20 in a single day. The same polling found the Republican’s overall edge grew by three points, to a total of five over the president. Romney gained four points with middle-class voters and now leads the president in that category by 10 points. The president also lost points among women as his advantage shrank from 10 to eight points.

Ahead of Thursday’s vice-presidential debate, a poll conducted by the Pew Research Center for the People & the Press poll on October 4-7, among 1,511 adults — 1,201 of them registered voters — found that 51% of respondents had an unfavorable impression of Vice President Joe Biden and 40% had an unfavorable view of his challenger, Congressman Paul Ryan. In September 2008, Biden’s unfavorable rating was only 31% as he prepared to take on then-challenger Governor Sarah Palin. 42% of independent voters expect Ryan to perform better than Biden, with 25% believing that the vice president would win the debate. 54% of voters are likely to watch the debate.