Fredreka Schouten

USA TODAY

Hillary Clinton's new focus on rival Bernie Sanders appears to be paying off — for Sanders.

The Vermont senator had raised $1.9 million as of Thursday morning, following attacks this week from Clinton and her surrogates. About 66,000 people have donated to Sanders' presidential campaign since Tuesday afternoon when his camp sent out a fundraising appeal, highlighting Clinton's denunciations of his universal health-care plan.

"The panic attacks and falsehoods being spread by the Clinton campaign have boomeranged on them," Sanders spokesman Michael Briggs said in an email about the fundraising surge. "Bernie is doing well in the polls by sticking to his message that we need to reform our corrupt campaign finance system that has helped keep in place our rigged economy."

After largely ignoring Sanders for much of the Democratic primary battle, Clinton's camp is paying lots of attention to the Vermont senator this week. Clinton, her campaign aides and her daughter, Chelsea, have unleashed a string of attacks on Sanders' policy proposals, describing his single-payer health-care plan as unrealistic and a threat to existing programs, such as Medicare.

The barrage comes as the race tightens. ADes Moines Register/Bloomberg Politics poll out Thursday shows the two statistically tied among likely Democratic caucusgoers. Support for Clinton has dropped by 9 percentage points in a month. Sanders, meanwhile, holds the edge in New Hampshire, according to a RealClearPolitics average of recent polls.

Sanders, whose fundraising has grown steadily in recent months, has invested heavily in television advertising to build momentum ahead of the early voting. In the past three weeks, he's spent about $4.7 million on TV commercials to Clinton's $3.7 million, resulting in 1,000 more Sanders ads on broadcast TV than Clinton commercials, according to the Associated Press and Kantar's Campaign Media Analysis Group.

The Iowa caucuses are Feb. 1. New Hamphire votes Feb. 9.

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