Months after telling Hillary Clinton the American people were "sick and tired of hearing about your damn emails," Bernie Sanders said the issue may be a drag on her as a battle rages ahead of California's Democratic primary on June 7.



In an interview that will air Sunday on CBS's "Face the Nation,'' Sanders said he plans to stay focused on core issues such as reforming health care and lowering college costs in the last few weeks of primaries. Still, he went furthest yet in saying Clinton's email issue could be a drain with voters.

"Now, you're right — the Inspector General just came out with a report, it was not a good report for Secretary Clinton," Sanders told host John Dickerson, according to a transcript provided by the network. "That is something that the American people, Democrats and delegates, are going to have to take a hard look at."

Trailing Clinton among pledged delegates collected through state primaries and caucuses, Sanders said super delegates — party leaders and elected officials not formally bound to any candidate — should, at the very least, cast their ballots at the Democratic National Convention in July with the candidate who carries a given state.



That would give Sanders a boost from states like Vermont, Washington, and Alaska, although Clinton prevailed in populous states such as New York, Florida, and Texas.



Sanders continued to press a case for super delegates to switch their allegiance to him from Clinton, regardless of state affiliation, and said the email controversy could become a drain on her in the general election.

"They will be keeping it in mind. I don't have to tell them that," he said. "I mean, everybody in America is keeping it in mind and the super delegates sure are."



Sanders trails Clinton by 1,769 to 1,499 in pledged delegates, according to an Associated Press count. When super delegates are included, Clinton's lead swells to 2,310 to 1,542, leaving the former secretary of state 73 short of clinching the nomination. She's likely to cross that mark when votes are tallied in New Jersey, one of six states to vote on June 7.



Speaking on ABC's "This Week with George Stephanopoulos," Sen. Dianne Feinstein, Democrat of California, said it was time for party unity.



"He ought to be able to read the sign posts as well as anybody else, and if he did that, he would know that it's all but over," she said of Sanders.



Still, Sanders insisted on CBS that "there is just a possibility that we may end up at the end of this nominating process with more pledged delegates than Hillary Clinton."



"I think we have a good chance to win here," Sanders said of California, the most populous U.S. state. Two opinion polls last week offered different outcomes for California. One showed the race basically a toss-up, with Clinton ahead by two points. The other put the former New York senator up by 18 points.



"Obviously if we don't do well in California, it will make our path much, much harder," Sanders said in a separate interview on NBC's "Meet the Press." "California is the big enchilada."



The State Department's inspector general found in a report made public on Wednesday that the email set-up violated department rules, that Clinton never sought permission for it, and that the proposal would have been rejected if she had. The report handed Clinton's Republican opponents a fresh line of attack — and Sanders, too, if he chose to take it.



Sanders won praise at a candidates' debate in October when he said, "Enough of the emails. Let's talk about the real issues facing America.'' At the time, his campaign used the comments in a fund-raising email.



Fast forward seven months and for Sanders, the delegates on offer on June 7 represent a last-ditch effort to close the gap with Clinton.



A strong performance in California may boost Sanders's case that super delegates should switch their allegiance to him on the basis of perceived electability against Donald Trump, the presumptive Republican nominee.



That argument so far has been driven by opinion polls showing Sanders faring better than Clinton in a hypothetical match up with Trump.



In another sign Sanders has taken off the gloves, his campaign late on Friday demanded the ouster of Connecticut Gov. Dannel Malloy and former Massachusetts Rep. Barney Frank from a key platform committee at the Democratic National Convention.



Democratic officials rejected Sanders's request on Saturday, the Associated Press reported.



In a statement, the Sanders campaign said Frank and Malloy were "aggressive attack surrogates" for Clinton. Sanders's lawyer said the pair can't work impartially "while laboring under such deeply held bias."



In a four-page letter hand-delivered to Democratic National Committee late Friday, Brad Deutsch, Sanders's campaign counsel, wrote of animosity by Frank toward Sanders dating to 1991.

Criticisms of Sanders by Frank and Malloy have gone beyond dispassionate ideological disagreement and have exposed a deeper professional, political and personal hostility toward the senator and his campaign, Deutsch said.



Frank on Saturday pondered the Sanders campaign's motive.



"I hope it is not to lay the basis for an inaccurate claim that he was unfairly denied the nomination, and I do see some elements of this," he told Politico.

Also this week, Sanders, keen for network airtime before the California vote, appeared to get a boost when presumptive Republican nominee Trump agreed to debate him to raise money for a charity. The billionaire businessman backed out on Friday, saying it would be "inappropriate" to debate the second-place Democrat.



Sanders may not have given up hope, though. "Maybe we'll get a call in five minutes and he'll say yes again," he said on CBS.