Ms. Ocasio-Cortez has raised more than $10.3 million over the past two years, millions of which she has deployed aggressively online, far outpacing her fellow House members.

Since the beginning of this election cycle in 2019, she’s spent $3.6 million on Facebook ads, including nearly $2.4 million since January, according to her campaign. The next biggest digital advertiser among House members in 2020 is Representative Adam Schiff of California, who spent $620,000 online, according to the tracking firm Advertising Analytics.

Indeed, Ms. Ocasio-Cortez’s online spending has outpaced those of most Senate campaigns this cycle, including well-funded candidates like Mark Kelly in Arizona, Sara Gideon in Maine and Senator Lindsey Graham of South Carolina.