In a speech on Wednesday evening, Sanders said that Clinton was “unqualified” to be president. He again alluded to payments she received for speeches she delivered to big banks and the fact that she is supported by a Super PAC, arguing that these items made her unqualified to be president.

Sanders’ comments came in response to an interview Clinton gave to MSNBC’s Morning Joe that some in the press interpreted as an argument that Sanders was the unqualified one. Clinton didn’t say that, though. She did say she felt Sanders “hadn’t done his homework and he’d been talking for more than a year about doing things that he obviously hadn’t really studied or understood,” a reference to Sanders’ interview with the editorial board of the New York Daily News in which he stumbled over questions about breaking up big banks, a central plank in his platform.

Related: Bernie Sanders Can’t Explain How He’d Break up the Banks

On the surface, Sanders’ claim that Clinton is unqualified is ridiculous — she served as a U.S. Senator for eight years and Secretary of State for four, not to mention being First Lady for eight years.

Right now, though, the race isn’t strictly about who will be president — it’s about who will be the Democratic nominee. Many of the Democrats who vote in the party’s primaries are progressives. For months, Sanders has tried to argue that Clinton is not qualified to represent those voters, given her close relationship with the financial industry and her generally hawkish approach to foreign policy.

Viewed through that lens, this latest line of attack is merely a continuation of the case Sanders has been making for months, though with much harsher language.

Last week, Clinton campaign officials complained about the tone the Sanders campaign had recently adopted, criticizing him for going negative. Well, now he is actually going negative. The voters in New York, Pennsylvania, California, and other states still waiting to make their choices will ultimately show if it was a good move.