Hillary Clinton, Bernie Sanders Mock GOP Debates

Both Democratic presidential candidates briefly set their differences aside on Sunday in Flint, Michigan, and touted their civil, substance-filled debate over the juvenile circus that their Republican counterparts engaged in last week in Detroit.

"We have our differences, but compare the substance of this debate with what you saw on the Republican stage last week," former Secretary of State Hillary Clinton said during the CNN debate, earning a large round of applause from the audience.

Sen. Bernie Sanders (I-Vt.) put it much more bluntly.

"We are, if elected president, going to invest a lot of money into mental health. When you watch these Republican debates, you know why we need to invest in mental health," he said.

The GOP debate on Thursday -- which included penis jokes, name-calling and personal attacks -- was widely seen as the election's ugliest yet. In contrast, Democrats stuck mostly to policy, such as discussions about trade, health care, gun control, fracking and Wall Street.

A Clinton campaign staffer, however, took issue with Sanders' "mental health" line.