One of the panelists for 'Reawakening America: From Poverty to Posperity' Princeton University professor Cornel West, left and media personality and host of the discussion, Tavis Smiley, right.

Give Professor Cornel West this much: in the pantheon of presidential insults, “global George Zimmerman” really is quite a gem.

And if it wasn’t for that blunt reaction to President Barack Obama after his 18-minute valediction to Trayvon Martin, West’s talk-radio partner, Tavis Smiley, might have taken the prize when he declared the speech as “weak as pre-sweetened Kool-Aid,” via tweet.

Never mind that if Obama had gone another route, and stood pat with his initial, and very generic, 66-word response to the George Zimmerman verdict, Smiley and West would have almost certainly declared Obama’s remarks to be “bland as unsweetened iced tea.”

Because no matter how the president reacted to this—or any situation—the pattern with Smiley and West is that it’s never good enough.

Criticism is fair, slander is not

Which doesn’t mean that the president shouldn’t be criticized. Like a few years ago, for instance, when I said Obama was “stupid” for involving himself in the fracas that followed Dr. Henry Louis Gates, Jr.’s arrest by a Cambridge cop. Or earlier this year, when I wrote that it was “plainly a failure” for Obama to have intervened militarily in Libya without coming up with a contingency plan for what unfolded later on in Benghazi.

Obama asked for this job, and when he missteps, I’m sure he can handle the criticism—no matter who that criticism comes from.

So, if Smiley and West have an issue, for instance, with the president’s admittedly ruthless prosecution of the war on terror, then they shouldn’t hesitate to air it. But when West noisily calls Obama a “global George Zimmerman,” it doesn’t shed any light on the issues—and just makes the once-universally admired scholar sound more like a crank.

Perhaps, though, the most revealing thing about Smiley and West’s intemperate brickbats—hurled from the left—is that they call for an ideological purity that they know is inconsistent with presidential decision-making.

And that’s a lot like what’s thrown at Obama by their ideological analogues on the right.

Sacrificing realism to score points

The nexus between “global George Zimmerman,” “pre-sweetened Kool-Aid” and the reaction of Fox News’ Sean Hannity—that what Obama meant by “could have been me” was that both he and Trayvon “smoked pot” and “did a little blow” as teenage boys—is the instinct to hammer Obama, rather than to realistically evaluate him as a president.

Never mind that the president used Mitt Romney’s health plan, extended George W. Bush’s tax cuts, doubled down in Afghanistan and helped bring the Dow back from the 6000s to the 15000s. Critics like Hannity will still oppose anything Obama proposes.

Just as Smiley and West—both progressives—seem not to have noticed that Obama got out of Iraq, signed federal sentencing reform, tripled the number of women on the Supreme Court, repealed Don’t Ask, Don’t Tell and offered a balanced, analytical, level-headed—but hopeful—personal reflection in the wake of the Trayvon Martin tragedy.

Which Smiley immediately pronounced “weak as pre-sweetened Kool-Aid”—even though Obama’s words received praise across the spectrum, from Trayvon’s parents to the president’s former rival, Sen. John McCain.

One-liners and pot-shots

Just like when West says civil rights leaders are on the “Obama plantation,” he’s sharing his script with former Congressman Allen West—the firebrand black Republican who once said that he’d lead black voters off of the Democrats’ “21st century plantation.” Or the time Dr. West remarked that Obama was scared of “free black men,” which sounded a lot like fast-food executive Herman Cain’s assessment that Obama isn’t a “real black man.”

I could go on, but I won’t.

The point isn’t that Smiley and West shouldn’t speak their minds—they should. But if they want us to take them seriously, then they’d be well-advised to come up with something better than one-liners and pot-shots.

Because like a lot of the criticism that comes from the other end of the spectrum, Smiley and West’s riffs are as weak as pre-sweetened…never mind. You know what I’m saying.

Follow @Swerdlick on Twitter.