Sexist comments. Failed business ventures. Caustic rhetoric. Unseemly business dealings.

For months, Republican opponents of Donald J. Trump hit him on myriad issues, to no avail. Now, the “super PAC” supporting Hillary Clinton’s campaign, Priorities USA, is picking up where Republicans left off, with two broadcast ads focusing on Mr. Trump’s remarks about women and a new online ad mocking his business exploits.

THE AD Over and over, Mr. Trump is interrupted in mid-sales pitch — for Trump Airlines, Trump University, Trump Steaks, and so on — with a red rubber stamp declaring “Scam,” “Failed” or “Fraud.” The bottom line: Far from the business genius he purports to be, Mr. Trump is no better than a “con man.”

THE IMPACT His detractors are of two minds about negative ads attacking Mr. Trump: Some believe his victory in the Republican primaries shows that they did not work; others say his exceptionally high unfavorable ratings show that they did. Operatives at Priorities USA say that many voters did not pay much attention to ads during the primary campaign — so expect to see a lot more.

Changing channels ...

Two Can Play

Even as Democrats have begun attacking Republican congressional candidates by linking them to their presumptive presidential nominee, the National Republican Senatorial Committee released a brutal new digital ad tying Democratic candidates to Hillary Clinton.