Is Hillary's biggest problem Sanders or servers?

Hillary Clinton's path to victory in Iowa is cluttered by the dueling problems of her email scandal and the excitement building behind her chief rival, both of which may threaten the outcome of a contest Clinton was once heavily favored to win.

Sen. Bernie Sanders' recent rise in Hawkeye State polls has coincided with a dip in support for Clinton, which occurred during several weeks of renewed attention to her private email use.

But Democrats seem to disagree on whether Clinton's slippage is due to her rival's growing popularity or her own inability to retire questions about her handling of potentially classified information while serving as secretary of state.

"It's pretty clearly Bernie Sanders' aspirational message and sort of the passion that he's tapped into," former Indiana Sen. Evan Bayh told the Washington Examiner of why he thinks Clinton's lead in Iowa has shrunk.