Does Harris’ approach to positioning DT as not serious have the potential to be an effective strategy?

One tactic that Harris seems like she is really trying to leverage is that Trump lacks the gravitas of a president. She referred to him as “not serious” in her DNC speech and continues to highlight it with her “next question please” about his race baiting.

However, Trump’s campaign seems to be leaning in to it with name calling and flippancy. For example, Stephen Cheung’s comment about the interview, “America was eagerly anticipating an interview where Comrade Kamala and Tampon Tim would actually answer questions—after she refused to do any interviews of press conferences for 39 days—but what they got was a shameful display of lying of policy positions and basic facts," Cheung said. "America tuned into a train wreck."

Seeing that a lot of Trump’s appeal seems to be his projection of strength, does this line of attack have potential to be effective?