Advertisers have spent more than $2.3 billion on the 15-week presidential race between Vice President Kamala Harris and former President Donald Trump, a stunning ad blitz during which Democrats have outspent Republicans by a total of about $1.4 billion to $933 million. By comparison, during the final 15 weeks of the 2020 presidential election, advertisers ran a total of about $1.7 billion worth of advertising for the White House race, and Democrats led Republicans by about $1 billion to $631 million, according to data from the ad tracking firm AdImpact.