Sarah Palin's most ardent supporters in "real America" love to suggest that those of us who don't buy into her silly shtick fail to grasp why they heart her, citing her realness, plain-spokenness and whatever else they can conjure up.

Folks, nice try, but as a native Texan, I've seen many politicians and wannabes over the years that had charm, wit, charisma and a twinkle in their eye.

Anyone who has listened to the Lone Star State's best football coaches will tell you that they can convince a mother and father to send their kid to hell to fetch a glass of ice water and will bring a better man back home. They could teach a politician or two how to connect with average Americans.

You want a media darling politician with substance? Try the late Gov. Ann Richards, a woman who could cut you deep but beam ear to ear with her motherly smile. But unlike Palin, she had a host of strong ideas in her head that actually made sense and appealed to a cross-section of folks.

Congressman Charlie Wilson, who died this week, was a smooth-talking Texan who loved to party hard, but when it came to politics, he knew how to get things done. The media loved him because he could sit with you and enjoy a beer over a barbecue, give a hilarious quote or two and explain foreign policy better than Henry Kissinger.

So why haven't I cottoned up to Palin? Because she desires to portray herself as a straight-talking politician who desires to lead a movement in the "lower 48th." But she is nothing more than a political celebrity willing to cash every check she can grab.

What truly exposed her? The ridiculous way in which she reacted last week to two political heavyweights using the word "retarded."

When it was reported that President Barack Obama's chief of staff Rahm Emanuel told a bunch of liberals that they were "f——-g retards" for threatening to run ads against fellow Democrats who weren't jumping on the health care reform bandwagon, Palin demanded his resignation.

As the mother of a child with Down syndrome, Palin has often used her bully pulpit to demand respect for the mentally challenged. Nothing wrong with that. It is an issue that is close to her heart and she should be a fierce advocate.

Yet when one of her biggest supporters, conservative talk radio host Rush Limbaugh, also castigated liberals by calling them retards, Palin ran away from being a mentally-challenged advocate by providing him cover — even trying to explain away his comments.

In an interview with Fox News Channel's Chris Wallace, Palin said Limbaugh was using satire, while Emanuel was blasting those who disagree with him. But anyone who can read or listen could understand that Limbaugh did the same thing as Emanuel. She even went further to agree with Limbaugh when he said liberals are "kooks."

Emanuel and Limbaugh used retard to describe folks they disagree with, but only Emanuel was wrong? Yep, that's how it is in Palin's world. The mentally- challenged advocate was quick to pounce on someone she disagrees with politically, but not her patron saint, Limbaugh.

Sarah, when you hold yourself up as a fierce protector of the mentally challenged, politics shouldn't enter into the equation. Either you oppose everyone who uses a word that you consider a slur, or you come across as a crass politician who is afraid to offend your chief booster.

Maybe you ought to listen to your spokeswoman, Meghan Stapleton, who likely thought you cared about the mentally challenged when she sent this e-mail to HotAir.com in regards to Limbaugh's comment: "Governor Palin believes crude and demeaning name-calling at the expense of others is disrespectful."

But knowing that wouldn't sit well with Limbaugh, you backed off and gave him cover.

See, if you were true to your cause, you would have demanded an on-air apology from Limbaugh and scolded him for using the word. Instead, you showed your true colors.

Sarah, I haven't bought into the fake "I'm-a-real-American" persona you are trying to portray. You slam the president for using teleprompters, but write crib notes on your hand to remember basic beliefs that should be easy to regurgitate. You decry the "lamestream" media, but you bask in its glory and have now joined its payroll as a Fox News contributor, even having them build a studio in your home (talk about media elite!). You give a speech riddled with falsehoods about the president and national security, and then try to shrug them off as the "lamestream" media attacking you.

You don't fool me, even as your legion of fans considers you the second coming of President Ronald Reagan.

You quit on the people who elected you to become a political celebrity, which your running mate decried about then-Sen. Barack Obama. You had the opportunity to show everyone that you're willing to take on anyone who crosses the line against those mentally challenged, and you failed to do so.

Please, make as much money as you can. Paraphrasing comedian Martin Lawrence, ride this train until the wheels fall off. But please, cut the crap. You're a crass politician with no true conviction. Your actions have shown that.

Roland S. Martin is an award-winning CNN analyst and the author of the forthcoming book "The First: President Barack Obama's Road to the White House as originally reported by Roland S. Martin." Please visit his website at www.RolandSMartin.com. To find out more about Roland S. Martin and read his past columns, visit the Creators Syndicate Web page at www.creators.com.