The Vermont senator was defending himself for a third day in a row Friday morning for calling Clinton not "qualified" to be president amid escalating rhetoric in the Democratic primary.
"I am trying to stay away from personal attacks on Hillary," Sanders told MSNBC.
But he also stood by his criticism of her in recent days and blamed the Clinton campaign for leaking a new strategy after her loss to Sanders in Wisconsin that included discrediting Sanders.
"What am I supposed to do?" Sanders said. "We got to fight back, and that's what we are trying to do."
And the independent senator pointed out that there's subject matter on Clinton he's avoided, subtly bringing up lines of attack on her that he has not pursued.
"How often have I talked about Hillary Clinton's emails? Not one word. How often have I talked about the Clinton Foundation fundraising?" Sanders said. "Let's get back to the issues."
Last year, Sanders famously said during a debate that he had had "enough" of the "damn emails" story -- referring to the private server Clinton maintained as secretary of State and private email system that is being investigated by the Justice Department.
He also was referencing scrutiny of the money that has poured into the Clinton's organization, which has done philanthropic work worldwide, and any potential conflicts of interest that may have arisen while she was secretary of state.
The comments came during an interview that was largely a do-over for Sanders on a New York Daily News sit-down published this week, for which he faced heat
over vague answers on his signature issue: breaking up big banks.
His dodging answer on Israeli settlements during that interview also raised eyebrows -- and he clarified his position on MSNBC on Friday.
"What I believe, first of all, is there are good people on both sides and there are political opportunists on both sides," Sanders said.
He noted that he is Jewish, has family in Israel and lived in Israel for a few months when he was younger, so he believes that Israel's peace, independence and security "is paramount."
"But you have to recognize the plight of the Palestinians," he said, calling the situation in Gaza "deplorable" and urging a "two-state solution" to be worked out by both sides.
Willie Geist pressed Sanders on whether he believed that "plight" was caused by Israel -- a major point of contention for pro-Israel activists and politicians who argue that the blame for the conflict rests squarely on the Palestinians.
Sanders took a position more critical of Israel, saying that though "Israel has a right to protect itself from terrorism," they have taken it too far.
He cited U.N. statistics that estimate more than 2,000 civilians have been killed in the wars in Gaza. Israel has disputed that number.
"Do I think that Israel reacted in a disproportionate way? I do," Sanders said. "I think that was a disproportionate reaction" even though it's a war, he added.