Sanders slams Trump for worrying about "Bill Clinton's sex life"

Democratic U.S. presidential candidate U.S. Senator Bernie Sanders answers a question at the Democratic presidential candidates debate at St. Anselm College in Manchester, New Hampshire December 19, 2015.

REUTERS/Brian Snyder

In his quest for the White House, Donald Trump took aim at former President Bill Clinton last week, saying it was "fair game" to criticize the current Democratic front-runner's husband over Clinton's past sexual behavior.

But Democratic presidential candidate Bernie Sanders doesn't approve of this campaign tack: He'd prefer his fellow 2016 contender to focus on the nation's wage gap, taxes, and climate change.

"We have enormous problems facing this country and I think we got more things to worry about than Bill Clinton's sexual life," Sanders told ABC News in an interview that aired Sunday.

"I think -- interestingly enough -- maybe Donald Trump might want to focus attention on climate change, understand that climate change is not a hoax, as he believes that it is," he added. "That maybe Donald Trump should understand that we should raise the minimum wage in this country, which he opposes. And maybe we should not be giving huge tax breaks to fellow billionaires like Donald Trump."

When pressed, in a separate interview with CNN, whether it was indeed "fair game" to impugn the former president over his sexual history, Sanders responded with a clear "no."

"I think we have got more important things to worry about in this country than Bill Clinton's sex life," he repeated.

Clinton is expected to hit the campaign trail for his wife over the next week, with events scheduled for the first-in-the-nation primary state of New Hampshire.

At least one Republican presidential candidate didn't seem to mind the former president's role in the 2016 election.

New Jersey Gov. Chris Christie, during a campaign stop in Salem, New Hampshire, told reporters, "I have great respect for Bill Clinton and I've gotten to know him over the years."

"He's out working for his wife -- good for him," Christie said Sunday. "My wife's working for me -- that's a good thing too."

Another GOP contender, however, has come out in defense of Trump's attack on Clinton.

In an interview with CNN, former Hewlett-Packard executive Carly Fiorina agreed that going after her rival's husband is "fair game," but also warned that such attacks would not be effective in defeating the Democratic front-runner in 2016.

"Any former president is fair game," Fiorina said. "The question is, how do you beat Hillary Clinton? And, in my opinion, that's not the way to beat Hillary Clinton."