As unlikeable as he is, one has to give credit to David Letterman for an obviously strong constitution and having excellent control of his emotions.

Within about a week of each other he had first lady Michelle Obama and President Obama as guests on his show.

Although expert analysts might have detected it, to the untrained eye Letterman did not appear to display openly his great love and admiration for the two. Although Letterman did appear to become misty-eyed when he heard the first lady list her husband’s epic accomplishments, in general his facial expressions did not betray his true feelings.

However, one viewer claimed he saw an unusual spasmodic-like trembling of Letterman’s right pants leg as he gazed at the president. That could have been caused by a tingling in his leg, similar to the one Christ Matthews experienced when he watched Obama orate.

Lettermen’s love for all things Obama and liberal has caused an unreasonable reaction among knee-jerk conservatives, some even calling for Letterman to be reined in by censors.

Which, of course, is unlikely, given the makeup of the Federal Communications Commission. A more likely happening is that the Federal Elections Commission could rule that Letterman’s show violates election laws in that it is a contributor to the Democratic Party and Obama campaign. The problem would be how to put a monetary value on Letterman’s show, just as it would be difficult to determine how much value the major evening news shows are to Democrats.

Conservatives should understand, though, that banning Letterman from the air waves, or even censuring him in the name of “fairness,” would be harmful.

Like talk show hosts Rush Limbaugh and Shawn Hannity, Letterman is preaching to the choir. Muzzling Letterman wouldn’t add to conservative votes, it would merely deprive these poor souls of what little entertainment they have. Better to leave them in their stupor.

Those who listen to Limbaugh or Hannity may be a cut above Letterman’s audience in smarts, but it is likely that nearly all who listen to them agree with them on most issues.

Similarly, most of those who are present in Letterman’s studio or watch him on their television sets think like Letterman, slow and unreasonable, and already share his love for liberals and all celebrities. To them, deep thinking is when they are deciding which video to buy. They’re people who are also fans of “Doncing with the Stahs,” “American Idol,” and reruns of “Everybody Loves Raymond.”

Letterman studio watchers are so stupid that they have to be prompted by stage hands to watch the “Applause” sign light up. That’s for two primary reasons, their short attention span and the fact that many of them can’t read.

It would be a blow to the liberal cause if Letterman were to quit his show and go into live, more overt politics, such as run for office, which at times seems to be his real ambition.

If Letterman had to discuss serious issues intelligently, he would immediately be revealed as the buffoon he is. In the absence of cue cards he would be lost, although the fellow in the White House has done pretty well, was wise enough to learn his lines before his speeches. Letterman doesn’t appear to have that ability.

On the other hand, politics might be better suited for Letterman, since he hasn’t made it as a comedian. Without the laugh sign and the boom-boom-bah from the band, no one would realize that Letterman has just told a joke.

He said the other night that while George Dubya Bush was president, his show let all but one or two of the show’s writers go. It seems that before and after Bush he was also without writers, at least ones who could write funny lines.

Republicans also should not be grumbling about the Obamas appearing on such shows as Letterman’s or Leno’s or “Saturday Night Live” or the newest daytime soap, “Katie,” starring the ex-heavyweight journalist Katie Couric.

That’s where a huge number of Americans get their “news.”

Rumor is that next up is for the Obamas, along with the Bidens, to appear on “Family Feud.” However, some advisers fear that the show’s format would be too inviting for Biden to say something stupid. Others point out that he has been acting stupid for a good while, and people seem to love him for it.