Partisan liberals might consider it an oxymoron, but there is such a thing as a conservative intellectual. Indeed, I used to be one.

Though I've moved away from the right since those days, I maintain many friendships with highly educated, impressively smart conservatives. Their number is many, their intellects mighty. This column is directed at them, because there's something I genuinely don't understand.

I can't grasp how an intelligent, well-read man or woman, regardless of ideological commitments, could watch the Republican debate in Milwaukee on Tuesday night and not come away disgusted. I certainly did. It was a familiar feeling.

I began to experience it regularly in the run-up to the Iraq War. That disgust propelled my leftward migration over the following years, and it's intensified since the rise of the populist insurgency known as the Tea Party.

Somehow, my friends on the right don't seem to hear anything troubling, anything intellectually offensive emanating from the mouths of the Republican candidates. And I just don't get it.

I don't just mean the obvious stuff. You know, the unprovoked and petty anti-intellectualism of Marco Rubio denigrating philosophers by contrasting them unfavorably to welders (and presumably people who work at other skilled trades as well). Or Rand Paul's nonsensical, conspiratorial musings about the Federal Reserve. Or Donald Trump's xenophobic promises to build a 2,000-mile wall along the U.S.-Mexican border and round up and deport eleven million undocumented immigrants. (If they're undocumented, how will we find them? House to house sweeps by armed agents of the state through poor and heavily Latino neighborhoods? That's either absurdly unfeasible, as Jeb Bush and John Kasich pointed out, or a program for American fascism.)

And neither do I merely mean the dumpsters full of dubious assertions that are by now so deeply embedded in conservative ideology that every candidate tosses them out without making even the most cursory effort to bolster them with facts. Like the claim that America's relatively slow growth rate in recent years is a product of our tax burden (when in fact tax rates were considerably higher during the high-growth decades following World War II). Or the related contention that taxes can be drastically cut without massively increasing the budget deficit because the cuts will spur such enormous growth that tax revenues will actually increase. Or the endlessly repeated alliterative vow that ObamaCare will be "repealed and replaced," while neglecting to admit, let alone defend, the fact that the replacements favored by the GOP candidates would almost certainly leave millions of those currently covered by the Affordable Care Act without insurance.

Actually, that's more than enough to leave me pretty disgusted.

And yet, at Tuesday's debate, there were so many other things that got me going more than usual. I'm talking about specific policy proposals that amounted to nothing more than transparent nonsense. Maybe a credulous viewer with no knowledge of history, public policy, economics, or how the government actually works could respond to these proposals with a nod and a cheer. But informed viewers? Educated men and women of the right? Conservative intellectuals? They should know better — and know enough to realize when they're being sold, or helping to sell, a bucket of BS.

The appropriate response to someone attempting to turn you into the victim of a hoax or a swindle is anger. It's insulting to be treated like a sucker, a chump. And yet, my conservative intellectual friends appear not to be bothered in the least.

And that I just don't understand.

Here are three concrete examples from Tuesday's debate of Republican candidates doing their best PT Barnum imitation.

1. More than once in the debate, Carly Fiorina proposed reducing the federal tax code — not the forms ordinary citizens use to file their taxes, but the body of laws that govern taxation in the United States — to three pages. From its current length of more than 74,000 pages. (The actual code amounts to something closer to 3,000 pages, with the rest taken up by supporting material, but let's leave that aside.)

Now, could the tax code be shortened and simplified? I'm sure it could be! Maybe we could go back to its length in 1984 (26,300 pages). Or even to its size at the end of World War II (8,200 pages), when the population stood at 140 million people and the economy was many times smaller and vastly less complex than it is now. But no: Fiorina wants us to believe the code can be shrunk to three pages. Which is obviously, indisputably, offensively ludicrous. How can conservative intellectuals be anything but outraged by such hucksterism?

2. Ted Cruz took the usual supply-side happy-talk about tax cuts producing massive economic benefits to new, unusually concrete levels, claiming that instituting a 10 percent flat personal income tax and a 16 percent value-added tax, and eliminating the payroll tax, the "death tax," the corporate income tax, and the IRS, and the departments of Commerce, Energy, and Housing and Urban Development, would lead "every income group" to "see double-digit increases…of at least 14 percent."

Fourteen percent increases in what? Cruz provided an example that indicated he meant a 14 percent increase in income: "So if you're a single mom, if you're making $40,000 a year, what that means is an extra about $5,000 in your pocket…" (A 14 percent raise on $40,000 in income amounts to an additional $5,600 a year.)

The evidence for this assertion can be found in a report prepared by the Tax Foundation, a Washington think tank that, among other things, scores the tax plans of Republican presidential candidates. In the report, readers will find the claim that "the economic growth that the plan would produce" through "increased incentives to work and invest," as well as from "a significant reduction in the service price of capital," would lead every income level (including that of a single mom earning $40,000 a year) to enjoy an increase in after-tax income of "at least 14.2 percent over the long term," with the "long term" defined as "over the next 10 years." (The top one percent, incidentally, would enjoy a 34.2 percent income boost in that same time period.)

Meaning: If you make a series of highly questionable supply-side assumptions and extrapolate out for 10 years from the first year of a Cruz administration in which Congress passes his radical tax plan in every particular, a single mom currently earning $40,000 in after-tax income will be earning $45,600 round about 2027.

That's one uncertain 14 percent pay raise.

3. Then there's foreign policy — a subject on which every single candidate aside from Rand Paul endorses what journalist Matthew Yglesias once aptly described as The Green Lantern Theory of Geopolitics, which amounts to the view that, like the second-tier superhero, the United States can accomplish anything it wishes in the world, provided it displays sufficient willpower.

Don't like Putin's annexation of Ukraine and meddling in Syria? Fiorina can face him down. Pissed off about China's muscle-flexing in the South China Sea? Trump will show them who's boss. Dying to finally knock ISIS from the Dark Ages back to the Stone Age? Rubio's your man. Itching to undo the Iran nuclear deal so we can put the Mullahs in their place? Cruz will get it done.

All that's needed is American leadership, and American power, and the will to use them both. Because with the U.S. military, all things are possible.

Except, of course, that they aren't.

Since September 11, conservative reflection on foreign affairs has retreated into magical thinking. Where, I wonder, are Henry Kissinger, George Shultz, Brent Scowcroft, James Baker, Condoleezza Rice, Robert Gates, and the other grown-ups who once ran Republican foreign policy? What do they think when they hear one presidential candidate after another blather ignorantly about the world, proudly displaying their indifference to history, contempt for diplomacy, and obliviousness to grand strategy? Why do they remain silent while their party's would-be leaders talk about the world as if they're writing tweets for Rush Limbaugh's radio show instead of aiming to demonstrate that they're qualified to lead the most powerful nation on the planet?

Intellectual compromises are sometimes necessary in democratic politics. But selling one's soul should not be.

The Republican Party's 2016 presidential candidates have descended into vapid, puerile bleating. Conservative intellectuals are better than this, smarter than this. The time has come for them to speak up and call the GOP field what it is: ignorant, insulting, and dangerous.