Ever since Bernie Sanders started posing a threat, Hillary Clinton has repeatedly tried throwing one accusation after another at the Vermont Senator in the hope that one of them would stick. First it was that he is unelectable, too liberal, and then he was not liberal enough on gun control, not supportive enough of President Obama, and risked reversing his signature healthcare initiative by making promises he could not keep. None of them stuck because they were not accurate and sometimes mutually contradictory. Was he too liberal or not liberal enough?

To say that Sanders wants to or risks reversing President Obama’s biggest accomplishment in healthcare is to distort his position. On the electability issue, there have been recent polls which show Sanders faring better than Clinton in matchups against Donald Trump, Ted Cruz, and other probable Republican candidates. Although this could be because Sanders hasn’t been the target of vicious Republican attack ads for the better part of the year like Hillary has. That will inevitably change if Sanders is the nominee or even becomes a serious contender for the nomination. In any case, even the electability argument doesn’t hold at the moment.

However, during the latest PBS Democratic debate, Hillary may finally have found one line of attack that may work: Sanders is a single-issue candidate. Listen to her closing statement in the debate last Thursday:

Clinton agreed with Sanders that big banks and Wall Street needed to be regulated, but she stressed that taking money out of politics wouldn’t solve all the problems. Even if these things were done, there would still be institutionalized racism, sexism, and discrimination against LGBT people. She vowed to, "... keep talking about tearing down all the barriers that stand in the way of Americans fulfilling their potential." The statement was met with thunderous applause from the audience. For Clinton, who was having a difficult patch with an unexpected narrow victory in Iowa and a heavy loss in New Hampshire, this surely must have been a welcome relief.

It is not difficult to see why it did resonate with the audience. It was a carefully constructed statement. She said that she would do not just what Sanders promised to do, but would also go beyond that. She was thus the more complete and well-rounded candidate. Also, unlike the other attacks, there was some truth to this. When I first heard Bernie Sanders last year rail against Wall Street and big banks and talk about the need to get unaccountable money out of politics, it was refreshing. I was especially impressed by his pointed refusal to have a super PAC that would pour millions of dollars into his campaign.

It was proof that he was a candidate who would walk the talk on campaign finance reform where others had only paid lip service to it. However, he has since overused this to the point that it now sounds repetitive. He answers almost every question on any topic with tirades against Wall Street and big corporations. In fact, in the very same debate, Sanders seemed virtually intent upon proving Clinton right when he said he would improve race relations by ending “tax breaks to billionaires.” It was a tone-deaf answer and may well be used by the Clinton campaign to convince African-American voters that Sanders does not understand their problems.

Sanders needs to clearly speak out more on other issues like foreign policy and mass incarceration in that disproportionately affect African Americans and Latinos. However, Bernie can blunt this line of attack if he wishes to. Unlike Clinton, who is seriously compromised on her ties to Wall Street, all Sanders needs to do is speak out more on these issues to show voters that he cares about them. In the meantime, expect more attempts from Clinton surrogates to paint Sanders as a "single-issue candidate."