As the MAGA faithful gather for another day of CPAC in Grapevine, Texas, they are openly celebrating what they believe is tantamount to a major midterms victory: keeping President Donald Trump from endorsing John Cornyn ahead of May’s GOP Senate primary runoff. MAGA world is taking a victory lap — and fresh comfort — in the receipts: A lack of significant spending and polling so far by not only Cornyn’s campaign, but also the NRSC and One Nation, the Senate Leadership Fund-aligned nonprofit. It amounts to a pattern the MAGA cohort reads as Washington making peace with a matchup between...