One of the motor homes parked at Las Vegas Motor Speedway over the weekend had a big sign in the window that said FREE DENNY. On Twitter there's a #StandWithDenny hashtag. And if you don't keep up with NASCAR, at this point you might be saying: Who the hell is Denny?

He's Denny Hamlin. Thirty-two years old, out of Virginia. Drives the 11 car for owner Joe Gibbs (yep, that Joe Gibbs). Occasionally parties with Michael Jordan. Best known for winning at Martinsville in 2010 with a torn ACL in his left knee -- then winning in Texas just three weeks after the surgery.

But now he's a hero to NASCAR fans two times over. First, he dared to criticize NASCAR's fancy new car. And second, after NASCAR fined him for his comments, he's refusing to pay.

Hence, FREE DENNY.

It would be easy to say that NASCAR is being petty and shortsighted and dumb to fine a driver for his honest comments. But it feels right, so let's go with it, and throw "sort of un-American" in the mix.

Hamlin finished third in Phoenix two weekends ago in a race where there were no passes for the lead in the last 189 laps. Afterward, this is what he said about this year's new version of the NASCAR race car, called the "Generation 6" car:

"I don't want to be the pessimist, but it did not race as good as our Generation 5 cars. This is more like what the Generation 5 was at the beginning. The teams hadn't figured out how to get the aero balance right. Right now, you just run single-file and you cannot get around the guy in front of you."

On the criticism scale, that sounds more like near beer than stout. But it touches a spot where NASCAR is easily bruised -- the quality of the racing. The sport is already dealing with declining TV ratings and ticket sales. The fear is that fans will quit coming if they expect to see a race and end up getting a motorcade.

So NASCAR fined Hamlin $25,000 and put out a statement: "While NASCAR gives its competitors ample leeway in voicing their opinions when it comes to a wide range of aspects about the sport, the sanctioning body will not tolerate publicly made comments by its drivers that denigrate the racing product."

In other words: Don't you dare talk about the one part of the sport that actually matters.

Hamlin responded by sending one of those extra-long Tweets, saying he was refusing to pay on principle, and that it's not about the money. (That's probably true: 25 grand isn't all that much to a driver who's made more than $50 million in his career.)

So Hamlin is appealing the fine. NASCAR apparently could suspend him or garnish the money from his future winnings, although nothing about NASCAR's rule book is completely clear. This is my favorite crazy thing about NASCAR: The rule book isn't available to the general public, and when people do get to see it, it's clear that NASCAR can invent new rules from race to race. Can you imagine if baseball kept its rules to itself and made up new ones depending on the situation? Actually, this would explain the Outfield-Infield Fly Rule from the Braves-Cardinals game.

It's not fair to pick on NASCAR, though -- most every sporting body is thin-skinned when it comes to criticism from the inside. David Stern, in particular, is always ready to use the Mallet of Loving Correction on players and coaches who say that a ref missed a call, or a timekeeper served up some home cooking. I understand, in general, that the boss doesn't want employees ripping the company all the time. There's a right to free speech, but not a right to free speech without consequences.

But (cue the John Philip Sousa) our country is built on the idea that our institutions are strong enough to stand up to criticism -- that, in fact, criticism is necessary to help those institutions get stronger. (OK, stand down with the Sousa. Too many sousaphones.)

Denny Hamlin might not have been supportive of NASCAR. He might not even have been accurate -- there was quite a bit of passing at the front in Vegas on Sunday. But surely he didn't do any serious damage to NASCAR with his comments. In fact, I'd argue that NASCAR did more damage to itself. In a sport built on the outlaw spirit, it hurts your image if you never let anybody say something outlaw-ish. Fans connect with drivers, and it only enhances that connection if the drivers get to act like real people, instead of sponsor-thanking machines.

Last October, after a huge wreck at Talladega, Dale Earnhardt Jr. ripped NASCAR for engineering the cars to force close-quarters racing. "I don't even want to go to Daytona or Talladega next year," he said, "but I ain't got much choice."

Now that was stout. But he drew no penalty from NASCAR. He did apologize a couple days later, and maybe that was enough. Then again, maybe NASCAR didn't want to upset its most popular driver.

Denny Hamlin hasn't apologized. Then again, he's not NASCAR's most popular driver. Except right now maybe he is.

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Questions? Comments? Challenges? Taunts? You can reach me at tommy.tomlinson@sportsonearth.com or on Twitter @tommytomlinson. None of my support for Denny Hamlin excuses the ridiculous photo on the home page of his website. What is he supposed to be? A Wall Street banker heading off to fight storms?