Guy Cecil, chief strategist for the pro-Clinton super PAC, Priorities USA Action, said he watched for months as Republicans let Trump carve out his place within the Republican Party relatively unimpeded. He has no plans to allow for a general election repeat.

“We learned that you can’t wait until the last minute to go after Trump,” Cecil told POLITICO in a wide-ranging interview.

His group has already been testing lines of attack, in part by analyzing the effectiveness of the very ads that Republican groups like the Club for Growth, American Future Fund and Our Principles PAC have aired against Trump. Cecil foreshadowed a brutal fall campaign that would question Trump’s character, his temperament and a history of enriching himself at the expense of others.

“He treats entire segments of the population like second and third-class citizens,” Cecil said. “That may be funny for a reality show but it’s not entertaining when he’s president of the United States.”