Sen. John Cornyn’s endorsement this week of Roy Moore for the U.S. Senate from Alabama is a new low not just for the former jurist and ex-Texas attorney general, but for the party he claims to love. We had hoped, as many have, that Cornyn would stand against the tide of populist, nativist and exclusionary politics that have come to dominate the Republican Party in Texas and elsewhere. That hope has now been all but extinguished. …

If taking the right course wasn’t hard, it wouldn’t require courage. Besides, Cornyn’s embrace of Moore doesn’t just put party over principle. It puts power over party.