As the candidate at the front of the pack, former vice president Joe Biden was certainly expecting to draw fire from other candidates during the second part of the first Democratic presidential debate, held Thursday night in Miami.

The first strike came from Rep. Eric Swalwell (D-Calif.), who noted that, when he was a kid, he heard Biden give a speech about passing the political torch to a new generation. It was a good dig at Biden's duration on the political scene, one that Biden acknowledged with a grin.

He was not grinning after the second strike.

That came from Sen. Kamala D. Harris (D-Calif.). During an exchange about race, Harris tried to interject, with the moderators from host network NBC waving her off. Harris, expressing exasperation, noted that she was the only black candidate on the stage and deserved to be heard. The tactic worked; she was given time to weigh in.

What followed was a pointed criticism of Biden’s recent comments about a segregationist Democratic senator with whom he had worked early in his career. But Harris tied that kerfuffle to a potentially more problematic issue for Biden: his opposition to busing to integrate schools in the 1970s. Harris had herself been the beneficiary of a busing program, she said (a claim her campaign quickly amplified on social media). Biden was caught off guard and ended up seeming to advocate the primacy of local decision-making on such issues, a states'-rights-esque position that was common among opponents of civil rights issues in the 1960s. It was one of the most incisive attacks in the history of American political debates, one that left the former vice president acknowledging that his time had expired in an apparent effort to change the subject.

It’s hard to gauge just how effective the line of argument will be. It’s easy, in the moment, to overestimate the political damage that will be done, though Harris simultaneously chipped away at two of Biden’s strengths. She both undercut the tacit argument that Biden would be able to easily fend off President Trump in a general election and raised issues that are probably of concern to black voters — who have disproportionately supported Biden.

We do have one immediate measure that Harris had an effect, though.

As we noted Wednesday, after round one of the debate, we can look at Google searches as a possible indicator of who is capturing the public’s imagination. On Wednesday, that was Sen. Cory Booker (D-N.J.) and Rep. Tulsi Gabbard (D-Hawaii), though former housing and urban development secretary Julián Castro also saw a big spike in search interest. Considering search traffic (and search spikes) as a metric is as much art as science — or, really, as much shooting in the dark as hitting targets. It’s not clear what, if anything, search tells us about the flow of the race.

We know that, on Thursday, the biggest spikes in search interest were seen by author Marianne Williamson, whose unusual debate answers drove people to Google to learn more about her. (The peak of all search interest in the debate came when she described Trump’s family separation policy as “kidnapping.”) Entrepreneur Andrew Yang also had a few moments in which he spurred some curiosity (his peak: talking about Russia as a threat to the United States), as did former Colorado governor John Hickenlooper (peak: talking about climate change).

Harris’s search interest didn’t spike quite as dramatically, peaking after her attack on Biden. Biden’s peak came early, when he defended Obama. It pushed more search interest than Harris’s later exchange with him.

According to Google, though, Harris had a much better night than that graph would show. She was the second-most-searched candidate (after Williamson) and was, at one point, the top trending search topic in the United States. (Biden was the fourth-most-searched among the candidates onstage.) Harris saw a 500 percent surge in search interest in the second half of the debate, when she launched her attack against Biden.

Again, this isn’t a poll. But this is also a Democratic primary race in which two dozen candidates are competing. A surge in attention for any one of them — especially at the expense of the best-polling candidate — is almost certainly significant. This isn’t new for Harris, mind you. Her campaign launch was also the one that captured the most public interest.

It’s hard to say, hours after the debate, how effective Harris’s attack was. If the goal was nothing more than to get people to pay attention to her, Google suggests that she was successful.