For Republicans, the Sunday shows are becoming one giant pileup on the interstate. You don’t want to look, afraid of what you might see. But the sheer awfulness attracts one’s curiosity. Donald Trump started the pileup, but Republicans by and large are doing little defensive driving. Instead, they’re careering through the guard rail, multiplying the political death toll.

Sen. Marco Rubio (R-Fla.) on CBS’s “Face the Nation” had another ghastly outing, making one wonder if his staff actually watches him before booking him for another interview. It can be excruciating to watch him these days:

DICKERSON: You said you didn’t trust Donald Trump with the nuclear codes. Do you trust Hillary Clinton with the nuclear codes?
RUBIO: You know, I think the argument goes deeper than that when it comes to her. And that is, what kind of foreign policy will she pursue and where will it lead us ultimately to make decisions like that dramatic as the one you just outlined? . . .
DICKERSON: But do you trust her with the codes?
RUBIO: Well, look, I think there’s a process for the presidency.
And once you assume the office, no matter who holds that office, I think that the reality and gravity of it always weighs on these people. It’s a very difficult issue to face. So, I would hope that I can trust no matter who wins with the nuclear codes. . . .
DICKERSON: Let me try it another way.
The presidency on national security issues sometimes comes down to one person by themselves in a room alone, no matter how much advice they have gotten. On those tough decisions, whether it’s about the nuclear codes or about the other kinds of decisions a single president can make, do you think that Donald Trump has better character and judgment in those alone situations than Hillary Clinton?
RUBIO: So, that’s the challenge Donald has over the next two, three months.
DICKERSON: Well, what does Senator Rubio think?
RUBIO: Well, but there’s a campaign. So, that’s what I’m going to watch now.

Oh for goodness’ sake. It’s distressing to see him wade into an argument, get bogged down and try to scramble back to shore. Never has he appeared so, well, small.

That wasn’t nearly as bad as former Arizona governor Jan Brewer, who gets the “prize” for the most idiotic defense of Trump on his racist remarks about Judge Gonzalo Curiel. On CNN, she declared, “In that respect I think that Judge Curiel has a stunning reputation and I don’t believe that Donald Trump meant it in the manner that he said it. I believe that he felt that he was being treated unfairly in regards to this issue.” Oooh, boy.

And Newt Gingrich, appearing on “Fox News Sunday,” is just a nonstop train wreck:

WALLACE: Given Trump’s business record, given the fact that his tax plan by independent analysis would add $10 trillion to the national debt over ten years, doesn’t Clinton have plenty to attack when it comes to Trump?
GINGRICH: She will make a lot of allegations. But let me just give you one fact from the director of national intelligence.
Last year, the estimate by the director of national intelligence staff is that the Chinese stole $360 billion in intellect intellectual property. That’s twice the total U.S. exports to China, last year alone.

Umm, what’s that got to do with Trump’s inane tax plan? (By the way, $360 billion is a lot less than $10 trillion.) It’s embarrassing when Gingrich carries Trump’s fetid water:

WALLACE: Now, Mr. Speaker, you can certainly argue about how Hillary Clinton handled Benghazi. But the fact is, the attack happened at 3:00 or 4:00 here in the afternoon in Washington. And she was working late into the night.
As I say, there’s plenty to attack her on. But why not stick to the facts?
GINGRICH: Well, first of all, I’ve had different people say different things about what she did that night and what her instructions were. Second —
WALLACE: She wasn’t asleep is the point.
GINGRICH: OK. She certainly —
WALLACE: Maybe she should have been, but she wasn’t.

Why does Gingrich feel compelled to defend a stupid lie, a factually indefensible accusation? It’s hard to believe Gingrich thinks his candidate has any principles whatsoever: “I think he stands for an evolving to come to grips with really big problems.”) After that “defense” of Trump, many might conclude neither one of them has any principle other than self-promotion.

Senate Majority Leader Mitch McConnell (R-Ky.) fared somewhat better. He tends to keep it short and generally doesn’t bother to defend Trump on any specifics. He made it clear the GOP’s platform will be its traditional platform, regardless of the nominee’s views. (“It’s my expectation that the platform will be a traditional Republican platform, not all that different from the one we had four years ago.”) McConnell treats Trump like an interloper — which he pretty much is.

He freely shares criticisms and pointedly declined to say if Trump is qualified. (“I’ll leave that to the American people to decide. You know, he won the Republican nomination fair and square. He got more votes than anybody else against a whole lot of well qualified candidates.”) McConnell of course is still endorsing him (unnecessarily in my book, but at least he is perfunctory about it), but that doesn’t mean he is defending him or trying to make favorable comparisons on Trump’s behalf.

To be frank, there is no way to insist credibly that Trump is stable, conservative and qualified. If you try, you wind up sounding unprincipled and obtuse. Better to say what McConnell does, which boils down to: I have nothing good to say about him, but as a party leader I have to back him — just nominally.