Democratic presidential candidate Sen. Bernie Sanders said Sunday that the controversies over Dr. Ben Carson’s past are not fair game for scrutiny.

Carson, a front-runner in several Republican presidential polls, is under the microscope for allegations that he embellished key parts of his biography.

Sanders, who received scrutiny earlier this year for his past writing, said on NBC’s “Meet the Press” that voters care more about the issues facing the country rather than investigations of past statements and events.

“When you look at Dr. Carson, to the best of my knowledge, this man does not believe that climate change is caused by human activity. This man wants to abolish Medicare, impacting tens of millions of seniors, and this man wants to give huge tax breaks to the rich. I think it might be a better idea, I know it's a crazy idea, but maybe we focus on the issues impacting the American people,” Sanders told NBC’s Chuck Todd.

“I think the reason that so many people are turned off to the political process has a lot to do with the fact that we’re not talking about the real issues impacting real people.”

Sanders is also receiving attention for his perceived jabs at former Sec. Hillary Clinton. While he has said he will not personally attack Clinton, he reiterated on "Meet the Press" that he disagrees with Clinton “on many, many issues." He also said last week that the investigation into her emails should “proceed unimpeded.”

Sanders, an independent senator from Vermont and self-described “democratic socialist,” said his views on personal attacks had not changed.

“My views on Hillary Clinton's emails are exactly what I said in the debate and right after the debate,” he said, referring to last month’s Democratic debate. “What I understand politics and elections to be about is to discuss differences of opinion. I intend to do that and do that vigorously. That does not mean that I’m making personal attacks against somebody I respect.”