We know what a gaffe is supposed to be: when a politician says something really stupid. What a gaffe really is, if you are a Republican, is when you accidentally tell the truth.
The classic recent example was when Representative Kevin McCarthy stated out loud something that everyone in the country with half a brain knows perfectly well: that the Benghazi hearings were a lying political witch hunt designed to destroy Hillary Clinton, with absolutely no substance. For the crime of saying that out loud, McCarthy had the speakership of the House taken away from him.
Well, any number of Republicans have now collaborated in perpetrating the latest gaffe. This happened in the day after Antonin Scalia died, when they openly announced that they were never going to give a consideration to anyone that Barack Obama nominated.
Now, let us deal with the reality here. Remember those people with half a brain I referred to above? Well, they all know something else, and that is that the Congressional Republicans are never going to let an Obama nomination get through the Senate. As usual, the gaffe was stating the truth out loud. They could have made all sorts of disingenuous statements about how seriously they were going to take this Constitutionally mandated process, and then just refused to let any Obama nominee survive the process- which we all know is exactly what they intend do. Instead, they let this very ugly cat out of the bag, and are now counting on the press to let them walk it back without consequences, which it undoubtedly will.
Secret assaults on the Constitution work so much better than public ones, particularly for Republicans, who swear such fealty to that document. Of course, anyone who is watching knows that the Constitution means nothing to them, except when it can be twisted to appear to support what they already intended to do; this is just one more example of that.