Senate Majority Leader Mitch McConnell has endorsed Paul’s national bid. But there are official endorsements and then there are endorsements with all the accouterments — fundraising help, stops on the campaign trail, leaning on fellow pols to get on board — and McConnell’s imprimatur is decidedly in the former category.

In the latest twist in a relationship between two politicians who in many respects are polar opposites, the Republican leader won’t be on hand for his junior senator’s White House campaign kickoff. Sources familiar with his decision insisted it’s not meant as a slight: McConnell is simply following through on his pledge not to campaign for Paul, lest he play favorites among the three other members of his conference planning or eyeing bids of their own.

“While McConnell has made his support for Rand known, he also has a job to do as majority leader,” said one Republican official with knowledge of their relationship. “With several members of his conference running for the same office, it’s just easier for him to do his day job that way.”