The flipside story to this is that Sen. Kamala Harris, of California, has seen a distinct bump in her support since her impassioned takedown of the former vice president last week at the first Democratic debate. There’s no doubt that Harris came prepared with material that her team believed to be a very weak and under-explored portion of Biden’s career.

Related: Watch Night 1 of the First Democratic Debate
Related: Watch Night 2 of the First Democratic Debate

While polling still shows Biden with the lead, Harris has moved up to third place in a tie with Sen. Elizabeth Warren, while both still sit behind Bernie:

Harris now polls at 12 percent, up 6 points from the previous week. This puts her in third place alongside Sen. Elizabeth Warren, who also polled at 12 percent, a one percent dip compared the previous week (a change within Morning Consult’s margin of error). Warren and Harris now stand behind Sen. Bernie Sanders — his support stands at 19 percent.

Joe Biden remains in the lead with 33 percent; however, his support saw a decline nearly as steep as Harris’s rise — he lost 5 points following the debates. Some of this erosion of support may have been Harris’s gain, and a segment of Biden’s base does view the California senator in a positive light: 15 percent of Biden backers said they would pick Harris as their second choice choice of candidate.

Harris’ targeted Biden takedown was calculated in a way to hurt him with a specific voting bloc. In South Carolina, a state which is being heavily targeted by Harris as her a big early primary stronghold, black voters make up a huge proportion of the Democratic primary voting base. So far, Biden continues to hold the support of African-Americans by large numbers. If Harris can chip away at that lead and start to build a perception of electability that surpasses Biden, she’ll start to peel away votes.

By attacking Biden’s record relating to the desegregation of school busing, Harris brought to light something that is rarely ever discussed, nor did most voters even know, about the former vice president’s political tenure, as Vox explains further:

“You also worked with [those segregationist senators] to oppose busing,” Harris said, speaking directly to Biden. “And there was a little girl in California who was part of the second class to integrate her public schools and she was bused to school every day. And that little girl was me.”

“I did not oppose busing in America,” Biden responded. “What I opposed is busing ordered by the Department of Education. That’s what I opposed.”

In raising busing specifically, Harris hit on a part of Biden’s record that Biden hasn’t really discussed publicly.

“When Biden said it wasn’t true that he supported anything that would have stopped the busing program that impacted her, he was correct,” the Biden campaign said. “None of [Biden’s] votes would have negatively impacted the Berkeley School Busing Program.”

Biden is aggressively responding to the accusations, as the story notes, but the damage has been done and put his campaign on the defense, a place where candidates never want to find themselves. During the debate, Biden appeared to concede that in the instance Harris was referring to, he did, in fact, oppose desegregation of school busing if it would be forced and directed by the federal Department of Education. Biden said he believed it was a state matter. That answer gave Harris more ammunition to fire back that if the state is engaged in segregationist policies, then all the more reason for the federal government to step in.

Harris gains the most post-debate support

According to post-debate polling, of which there is still very little, Harris alone seems to be the largest beneficiary of the first debate:

No other candidate saw the kind of surge Harris did following the debates. Buttigieg and former Texas Congressman Beto O’Rourke dropped slightly (Buttigieg fell from 7 percent to 6 percent; O’Rouke fell from 4 to 2 percent) but, again, these drops were within the poll’s margin of error.

Those results aren’t shocking for Beto O’Rourke who turned in a rather weak performance on Wednesday night in the first round. Perhaps more surprising is to see Pete Buttigieg’s support slip a little as a result of his debate performance. This may finally indicate that voters who quickly became obsessed with Buttigieg as a fresh face are cooling off to him in the backdrop of a national campaign where a more aggressive style is favored, especially against Donald Trump.

Harris clearly won the night, perhaps from this one exchange alone. If the goal of the debates is to give Democratic primary voters a reason to consider your candidacy and picture you fighting President Trump in the general election next year, then Harris’ calculated takedown of Biden was set up as a preview of how she would intend to attack the current President.