With time short before Monday's caucuses in Iowa kick off the presidential nominating contests,
Clinton was joined by
She's also ramped up her criticism of Sanders' proposal for a government-run healthcare system, warning voters Friday that it could jeopardize gains made under President Obama while opening a "terrible debate" over an idea that will "never, ever happen."
Sanders has rejected Clinton's criticisms, saying he was "disturbed" by "inaccurate statements" from her campaign. The Vermont senator — who stumped Saturday with academic, author and activist Cornel West and the rock band Vampire Weekend — pointed to his poor rating from the
Sanders also made pointed references to Clinton's support on Wall Street, including speaking fees she's received from firms like Goldman Sachs.
"We do not raise our money from Wall Street, from investment banks, the pharmaceutical industry," he said. "We are raising our money from the middle class and working families of this country."
The battle between Sanders and Clinton reflects a long-running fault line between the liberal and centrist wings of the Democratic Party, and Sanders' potential for a strong performance in the caucuses depends largely on his ability to convince voters that his uncompromising vision is worthy of support.
"There's always a conflict between the purists and the pragmatists," said Dennis Goldford, a political science professor at
The closely watched Des Moines Register poll, which was released in partnership with Bloomberg on Saturday, showed Clinton leading 45% to 42% among likely Democratic caucusgoers.
A third candidate, former Maryland Gov. Martin O'Malley, trailed with 3%. The margin of error for the poll, which was conducted Jan. 26-29, was plus or minus 4 percentage points.
Despite the tightness of the race, there were some signs of strength for Clinton. While 69% of Sanders supporters said their minds were made up, a significantly larger portion of Clinton's backers, 83%, said the same thing.
However, when Iowans were asked who "cares about people like you," Sanders was ahead, 51% to 37%.
Seeking any kind of edge going into the caucuses, the campaigns repeatedly fired accusations at each other Saturday over whether to add more debates in the coming months, the latest turn in a long-running subplot in the Democratic campaign.
Both campaigns announced Saturday that they had agreed to four more debates on top of the original six organized by the Democratic National Committee. But in a sign of how fraught the primary battle had become, they spent the day sparring publicly over exactly when and where the contests would be held.
At one point, Clinton campaign chairman
Sanders campaign manager Jeff Weaver responded by saying Clinton had reversed her earlier rejection of a Michigan debate. Then he pushed for a debate in Brooklyn, N.Y., Sanders' hometown and the location of Clinton's campaign headquarters.
"Why won't they debate in Brooklyn?" Weaver said in a statement. "What's the matter with Brooklyn?"
In his exasperated reply, Podesta said the Clinton campaign was ready to work out a deal. "There is nothing worse than a debate about debates," he said. "Enough of the games."