Why haven't responsible Republicans spoken out against her?

As for the underwear bomber, Umar Farouk Abdulmutallab, who nearly blew up a passenger plane on Christmas Day, yes, Obama took three days to comment on the incident—though, as many have since noted, Bush took six days to say anything about the shoe bomber, Richard Reid (and no Democrat made an issue of his reticence).

Reading Abdulmutallab his Miranda rights may have seemed a stretch (Obama the law professor!), but it turns out Reid was read his rights, too. More to the point, in neither case did the suspect use the occasion to clam up. As Richard Clarke, the former White House counterterrorism chief under Presidents Clinton and Bush, has noted, Abdulmutallab briefly went quiet because the FBI agents read him his rights while he was under sedation, but after he woke up, he resumed talking quite freely.

Palin's words (which she read with a venom unbecoming to one who, by her own admission, hadn't thought a whit about foreign affairs until 18 months ago) are not merely false. They're dangerous.

If there is a terrorist attack on the United States in the next few years, we could deal with it more confidently, and respond more effectively, if the president were able to rally a spirit of national unity. George W. Bush was given a chance to do this after Sept. 11 and, despite some initial fumbling, rose well to the occasion, at least for a few months.

But if the Republican Party's most popular aspirant declares that the sitting president doesn't know we're at war, isn't even a commander-in-chief (and crowds roar at this charge with approval), then Obama would have a much harder time repairing a wounded nation.

Palin, of course, is not alone in this irresponsible fraudulence. Just last week, Rep. John Boehner, R-Ohio, the House minority leader, casually said that Obama is taking a "pre-Sept. 11" approach to fighting terrorism.

Nobody is suggesting that Boehner run for higher office. But the tea-partiers are screaming, "Run, Sarah, run!" At the Nashville party on Saturday, someone in the audience asked her about the prospects for what he called the "two words that scare liberals—President Palin."

Let's be clear on why those words should terrify anyone with a thinking brain. Palin is someone who has clearly never seriously thought through any issue of national importance on her own. She's excellent at reciting a raucous speech, but she can't improvise a coherent sentence, which usually reflects an inability to form a coherent idea. (At Nashville, she even had to scribble her five-word legislative agenda on her palm, and glanced down at it during the Q&A.) She is deluded enough to believe (or at least to say Sunday morning on Fox News) that her brief, aborted stint as Alaska's governor gave her more executive experience than President Obama has even now. She believes that the country should elect leaders, including presumably herself, who seek solutions in "divine intervention."

Is this how Republicans who aspire to true leadership want to shape their party's ideas and their country's discourse? If not, they should hop off the circus wagon now.