In the Final Week of the Campaign DeSantis publish the most devastating Ad calling Gillum "Venezuela Gillum Socialist" and that stuck. Gillum underperformed Hillary Clinton in Miami-Dade costing him the Election.
People don't care about TV ads. Campaigns keep lighting money on fire with ad buys, but as far as I know, no reputable study suggests they move the electorate in any lasting, noteworthy way.
There are a few obvious exceptions, like Joni Ernst’s castrating ad and Jason Kander’s background check ad were very notable in shifting their races
