There will be time to argue about Kamala Harris, an average politician at best, a woman who Americans know well and don’t much like, giving her a 39 percent approval rating on average, the same as President Biden’s. Democrats have stronger candidates, and it’s a damn shame that Biden didn’t remain neutral so that we could have an open competition to test that. With Biden’s endorsement, Harris has a lock on the nomination, barring some shock. Biden delegates can reject his advice, so a fair fight remains a technical possibility. But party rules say delegates should reflect the views of their ca…