The Republican National Committee has been dangling a “Trump Life Membership” to entice small contributors to give online. The party’s Senate campaign arm has been hawking an “Official Trump Majority Membership.” And the committee devoted to winning back the House has been touting Mr. Trump’s nearly every public utterance, talking up a nonexistent Trump social media network and urging donations to “retake Trump’s Majority.”

Six months after Mr. Trump left office, the key to online fund-raising success for the Republican Party in 2021 can largely be summed up in the three words it used to identify the sender of a recent email solicitation: “Trump! Trump! Trump!”

The fund-raising language of party committees is among the most finely tuned messaging in politics, with every word designed to motivate more people to give more money online. And all that testing has yielded Trump-themed gimmicks and giveaways including Trump pint glasses, Trump-signed pictures, Trump event tickets and Trump T-shirts — just from the National Republican Senatorial Committee in the month of July.