Updated

Mitt Romney's strong debate performance Wednesday night has generated $12 million in online contributions, his campaign said, as well as a surge in volunteers and bigger crowds at his events.

The $12 million the campaign reports raising in less than 48 hours after the debate tops the amount Mr. Romney raised in the days after announcing Rep. Paul Ryan, R.-Wis., as his running mate and the Supreme Court's decision to uphold a major plank of the president's health-care law. Sixty percent of the money came from first-time donors, the campaign said, according to The Wall Street Journal.

Mr. Romney's debate performance triggered additional volunteers for the GOP's next national turnout drive on Saturday. The number of people who signed up to volunteer to make calls, knock on doors and sign up supporters for Mr. Romney has shot up by nearly 63% since Wednesday night, campaign officials said. The Republican National Committee, working in conjunction with the Romney campaign and its various state parties, expects to contact nearly two million voters on Saturday and roughly five million for the week.

It is too early to tell how much Mr. Romney moved the needle Wednesday night, and the early evidence is more anecdotal than empirical: Volunteers in Nevada lined up before campaign staff could open the doors on Thursday morning, the campaign said, and larger-than-usual groups showed up to work at field offices across the country. The campaign said it added more than 300,000 new Facebook friends.

The challenge for Romney in the weeks ahead will be translating this jolt of energy into votes in a race that saw the Republican nominee enter the first debate trailing President Barack Obama in most of the states that will decide the election.

President Barack Obama's campaign and Democrats have raised $181 million combined in September, pulling in the most money in one month during his re-election bid.

President Barack Obama's campaign and Democrats said Saturday they raised a combined $181 million in September, pulling in the most money in one month during his re-election bid, according to The Associated Press.

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