At a campaign event for Donald J. Trump in Mississippi last weekend, Lynette Hardaway and Rochelle Richardson — two African-American YouTube stars who go by the names Diamond and Silk — rallied the roaring crowd with a plea. “Ditch and switch! Ditch and switch!” they yelled.
The pitch was directed at Democrats and independents in the audience, urging them to become Republicans and vote for Mr. Trump if they really want to show their support.
It could be an important strategy for Mr. Trump as the pace of primary season picks up, and he looks to turn his raucous campaign events into voters, delegates and ultimately the Republican nomination. To accomplish that, Mr. Trump will be relying on people who do not tend to vote and trying to persuade some Democrats and independents to change parties so that they can vote in states that allow only registered Republicans to participate.