Political influencer Kerry Robertson takes a selfie before the 2024 Democratic National Convention in Chicago. (AP Photo/Charles Rex Arbogast)It’s usually easy to identify paid political ads on TV with their flashy photos and dramatic text overlays, often punctuated with the phrase “I’m [candidate name], and I approve this message.” But when paid political content is posted by influencers in a more casual and seemingly organic way, it can be dif…