This summer, Times Opinion organized a new project to follow a group of young, undecided voters through the election, and we kicked it off just before the Democratic National Convention with a wide-ranging discussion about Donald Trump and Kamala Harris. The group had very specific opinions about Mr. Trump. The Jan. 6, 2021 attack on the Capitol was searing for many of them, some of whom were teenagers at the time, and they held Mr. Trump responsible. They called him a traitor, a narcissist, untrustworthy. Some worried he would fight another election loss.

And yet, the group was even more negative about Ms. Harris.

When we asked them to rate Ms. Harris and Mr. Trump on a scale of 0 to 10 (with zero being extremely negative), Ms. Harris got mostly threes — she did no better than a five. Mr. Trump got mostly fours and fives, and topped out with a seven.

But there was a difference in how the group criticized the two candidates. Most of them had doubts about Ms. Harris — how she would improve the economy, whether she supported Israel, if she was patriotic, what she knew about President Biden’s cognitive abilities. They labeled her disingenuous, invisible, fake. Most were suspicious about Ms. Harris — yet most detested Mr. Trump. They knew him.

If Ms. Harris was losing the battle against Mr. Trump in our first discussion, I thought she had a chance to win the war. When presidential races get down to the wire, the candidate who is less well-known and running as an agent of change often has the better chance to make a persuasive impression with a larger share of Americans who are on the fence or just tuning into the race — I think of Bill Clinton, George W. Bush, Barack Obama and the 2016 version of Mr. Trump in this regard — rather than the candidate who has a cemented negative image among many voters.

So as I sat inside the United Center in Chicago on Thursday night and listened to Ms. Harris’s convention speech, I wondered if it would change the minds of anyone in our group, who I’d asked to check out her speech.

Turns out it did. When I followed up with our group over the last few days, to ask if their views had shifted, five of them said they were more likely to vote for Ms. Harris after listening to her speech; three said they were less likely; and six said the speech made no impact. I also asked the 14 of them to rate Ms. Harris again; they gave her mostly threes and fours, as well as a six and a seven. No one came away from the speech giving her a lower rating than they had before. (We’ll next ask the group to rate Ms. Harris and Mr. Trump after their first debate.)