1 big thing: Kamala Harris is debate's Twitter winner

Sen. Kamala Harris drew more tweets than any other candidate in Thursday's debate, according to data provided to Axios' Neal Rothschild by Sprout Social.

Why it matters: That online velocity is likely to translate beyond social media to polls, fundraising and other engines of momentum in the crowded field.

What's going on: Tweets mentioning Harris' Twitter handle generated 23% more interactions — likes, comments, retweets— than those about the next closest Democrat, Pete Buttigieg.

Buttigieg generated the second-most interactions and had the most interactions per tweet.

the second-most interactions and had the most interactions per tweet. The other winner: Julián Castro generated the highest totals in relation to his place in the polls — 11th, per Real Clear Politics.

Julián Castro generated the highest totals in relation to his place in the polls — 11th, per Real Clear Politics. The loser: Biden's fifth place in interactions was the worst compared to his polling position (first).

Demographic breakdown, per Sprout Social:

Highest proportion of interactions by men:

Andrew Yang: 71% Rep. Tulsi Gabbard: 62%

Highest proportion of interactions by women:

Sen. Amy Klobuchar: 56% Julián Castro: 55%

Highest proportion among ages 18-24:

Andrew Yang: 43% John Hickenlooper: 40%

Highest proportion among age 55+: