Poll: Sanders pulls within 6 points of Clinton in Iowa
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Sen. Bernie SandersBernie SandersTrump: Why didn't protesters vote? Trump nominees dodge 'climate denier' charge Sanders on women's march: Trump 'made a big mistake' MORE (I-Vt.) is closing the gap with Democratic front-runner Hillary ClintonHillary Rodham ClintonSNL honors Obama with emotional musical tribute Trump: Why didn't protesters vote? Biggest Dem donor thinks party needs new message MORE in Iowa, a new poll released Tuesday finds. 

A new Public Policy Polling survey found that the former secretary of State leads Sanders 46 to 40 percent, down from an 18 point lead last month.

The new PPP survey is the latest sign that the race is tightening between the two Democratic rivals weeks before the first-in-the-nation caucuses. Another poll released Tuesday shows Sanders surpassing Clinton in Iowa, 49 to 44 percent, overtaking an 11 point deficit the previous month.

In the PPP poll, the Democratic front-runner’s favorable rating remains relatively stagnant from last month at 72 percent to 22 percent unfavorable. But Sanders’s favorable rating has surged to 79 percent to 13 percent unfavorable. Last month, the Vermont senator received a rating of 65 percent favorable to 23 percent unfavorable. 

Former Maryland Gov. Martin O’Malley lags far behind at 8 percent. The poll also found that his candidacy is boosting Clinton’s support in Iowa. O’Malley supporters prefer Sanders to Clinton, 43 to 20 percent.

The poll was conducted from Jan. 8 to 10 and surveyed 580 likely Democratic caucusgoers with a margin of error of 4.1 percentage points.