WASHINGTON — A group of high-profile Republican strategists is working with a conservative billionaire on a proposal to mount one of the most provocative campaigns of the “super PAC” era and attack President Obama in ways that Republicans have so far shied away from.

Timed to upend the Democratic National Convention in September, the plan would “do exactly what John McCain would not let us do,” the strategists wrote.

The plan, which is awaiting approval, calls for running commercials linking Mr. Obama to incendiary comments by his former spiritual adviser, the Rev. Jeremiah A. Wright Jr., whose race-related sermons made him a highly charged figure in the 2008 campaign.

“The world is about to see Jeremiah Wright and understand his influence on Barack Obama for the first time in a big, attention-arresting way,” says the proposal, which was overseen by Fred Davis and commissioned by Joe Ricketts, the founder of the brokerage firm TD Ameritrade. Mr. Ricketts is increasingly putting his fortune to work in conservative politics.