Mrs. Clinton has often flourished in the wake of boorish behavior: her husband’s affair with Monica Lewinsky, Kenneth W. Starr’s investigation of her husband, the congressional impeachment proceedings. Women rallied to her side during her 2000 Senate race after her Republican opponent, Representative Rick A. Lazio, invaded her personal space during one debate, and they helped her win the 2008 New Hampshire primary shortly after Barack Obama dismissively said she was “likable enough.”

Yet Mr. Trump said he was determined not to fall into those traps.

In a telephone interview, he noted that women did not like seeing Mrs. Clinton insulted or bullied by men. He said he wanted to be more strategic, by calling into question Mrs. Clinton’s judgment in her reaction to Mr. Clinton’s affairs — people close to the couple have said she was involved in efforts to discredit the women — and in her response to crises like Benghazi.

“Just getting nasty with Hillary won’t work,” Mr. Trump said. “You really have to get people to look hard at her character, and to get women to ask themselves if Hillary is truly sincere and authentic. Because she has been really ugly in trying to destroy Bill’s mistresses, and she is pandering to women so obviously when she is only interested in getting power.”

He acknowledged that Republicans tried to discredit her judgment in the marathon Benghazi hearing in the fall, to little avail. But he said that he would be more pointed and memorable in linking her to the failings and deaths in Libya, and that the debate would have a vastly larger television audience than the hearing. Still, advisers of Mrs. Clinton pointed to her face-off with the Republican-led Benghazi committee as a sign of her unflappability.