Let's talk a little bit about racism, and about the sometimes subtle, sometimes overt ways in which it is communicated and perpetuated. And the text for today's exploration comes to us courtesy of Tuesday's broadcast by talk-radio host Rush Limbaugh.

On its face, Limbaugh's topic for the day had nothing to do with race. It involved Kenneth Starr, the conservative attorney who back in the '90s had turned an investigation into the Clintons' Whitewater investments into a meticulous, downright prurient examination of Bill Clinton's sex life, which Starr documented in exquisite detail.

Today, Starr is back in the headlines. Twenty years after the fact, Donald Trump is resurrecting many of the charges against Clinton that Starr first raised, and 20 years later Starr himself is distinctly unhappy about it. In comments this week, Starr praised Bill Clinton highly, especially for his post-presidential charity work, and expressed regret about the consequences of his investigation on the course of American politics.

"His genuine empathy for human beings is absolutely clear," Starr said, describing Clinton. "It is powerful, it is palpable and the folks of Arkansas really understood that about him -- that he genuinely cared. The 'I feel your pain' is absolutely genuine. President Clinton was and perhaps still is the most gifted politician of the baby boomer generation. He just has remarkable gifts.'"

Starr is in the news for another reason as well. In 2010 he was named president of Baylor University, the conservative Baptist university in Texas, and for the moment at least he still holds that job. One of Starr's proudest accomplishments in that role has been the reinvigoration of Baylor's football program, which has won 32 games in the past three seasons. But in one of the ironies of history, the man who wrote his name into the history books for his obsessive investigation into a president's sex life is now under attack for ignoring and downplaying allegations of rape and sexual assault by members of Baylor's football team. Starr's handling of that situation has become a major scandal, and he is unlikely to survive as university president.

That's all pretty strange, but in the crackpot world of Rush Limbaugh, these things are twisted into almost unrecognizable form.  According to the convoluted story that Limbaugh spun for his listeners Tuesday, the scandal now engulfing Starr is actually the work of the devious Clintons, who are taking long-delayed vengeance against their one-time nemesis. (As to how the Clintons could pull off such a feat -- don't ask. They are the Clintons, after all.)

And the nice words that Starr uttered recently about President Clinton? They too become part of the tale, as Starr's way of begging the Clintons for mercy.

Like I said, it's bizarre in its own right. So where does race come into this? It doesn't, and yet ... Limbaugh ensures that it does.

In describing the scandal at Baylor, Limbaugh told his listeners Tuesday that Starr is "under heavy investigation for looking the other way when black football players raped co-eds." Apparently, it's important to Limbaugh that his listeners know that these weren't just football players. It was important that his listeners know that these men raping helpless co-eds were BLACK football players.

That inclusion of what ought to be an irrelevant detail wasn't accidental. We know it wasn't accidental because later in the same broadcast, Limbaugh again used that exact phrasing: "He's under heavy investigation for looking the other way when black football players raped co-eds."

Because of course, the fact that they're black makes it so much worse. It titillates his listeners and quietly validates their bias, and for that they love him.

This didn't come out of nowhere. Limbaugh has a long history of racist remarks. He has called for the abolition of the NBA. "Call it the TBA, the Thug Basketball Association, and stop calling them teams. Call 'em gangs," he said. And the NFL? It "too often looks like a game between the Bloods and the Crips without any weapons." He also likes to describe people such as Halle Berry and President Obama as "Halfrican Americans." And on and on it goes.

In a society in which racism clearly had no place, the nation's most popular talk-radio host wouldn't be perpetrating and legitimizing it. His success tells us that racism not only still has a place, it clearly has a lucrative market. And as the success of Donald Trump is making clear, it also still has a powerful hold on our politics. As with Limbaugh, it is not by any means the sole reason for Trump's popularity. But it's there, clear as day.