After weeks of internal White House strategy sessions, the president and his aides have devised a confrontational election-season approach that focuses on Mr. Biden’s accomplishments coupled with an aggressive political assault on the G.O.P., including the poll-tested phrase he began using this spring: “ultra-MAGA Republicans.”

Now, with Mr. Trump once again at the center of a criminal investigation, this time over his handling of classified documents, Mr. Biden has seized the moment to press a case that voters cannot risk a return to a party in the thrall of the former president…

For the White House, Mr. Biden’s amped-up language is one half of a tricky balancing act. Fresh off a series of legislative successes, the president is determined to use the next two months to remind voters about the promises he made good on. At the same time, Mr. Biden wants to keep voters focused squarely on Republicans and their agenda.

Mr. Bates, the White House spokesman, said the goal was to do both at the same time.