ABC's decision to fire Roseanne Barr in the wake of her racist tweet was admirable.

The network's choice does not violate her constitutional right to free speech.

We should not reward vitriolic racism with fame and stardom.

Speech that is polite or uncontroversial is rarely in need of protection. It is speech that is disturbing, offensive, abhorrent, even, that is often in need of defense.

But there are lines and limits, and we should endeavor to have a rational, common-sense approach when figuring out exactly where those lines should be drawn and where those limits should be enforced.

The First Amendment prohibits Congress from passing a law "abridging the freedom of speech." But the government has no involvement in most of the free-speech controversies that seem to dominate the Twittersphere and the cultural zeitgeist.

That was true regarding the NFL's decision to fine teams whose players kneel during the anthem, and it is also true regarding ABC's decision to fire Roseanne Barr after she tweeted racist and disturbing comments about Valerie Jarrett, a former top adviser to President Barack Obama.

You can make a case that people and corporations should strive to honor the spirit of the First Amendment even in areas where government involvement is nonexistent. But ultimately, private entities have the right to decide whom they want to employ and how they want to represent themselves to the world.

After the NFL announced its new policy, I argued that in seeking to respect the flag, the NFL was actually insulting it far more than were the players who opted to kneel. I still believe that. The organization was acting within its rights, but that does not make its decision any less disappointing or perverse.

In representing our country's laws and values, the flag stands for the freedoms of expression and speech. Football fans might find the act of kneeling disrespectful — as I do — but the players who do it are expressing a political opinion and adding their voices to the conversation surrounding race relations in the US.

Roseanne, by contrast, did not add anything to our discourse with her tweet insisting that "muslim brotherhood & planet of the apes had a baby=vj." Racism has long counted among its preferred expressions the dehumanization of minorities and the characterization of them as animals. History provides many examples. Literature adds even more: Shakespeare's Shylock and Othello and Kafka's Gregor Samsa, to name just a few.

America's children are already growing up with the idea that our nation rewards lies, sexual impropriety, and intolerance with political office. Kudos to ABC for proving standards still exist.

There's a caveat here: It has become increasingly apparent that the right and the left are often in disagreement about what constitutes racism, sexism, or any other form of discrimination. As long as we can't universally define our terms, we'll be endangering the voices of those who hold contrarian — but not malicious — views. It can't be that every time a conservative makes an argument against affirmative action or abortion the person is smeared as racist or sexist and thus launching us into a conversation about who has a right to speak where and about what.

Both sides of the political spectrum have work to do. Leftists need to engage in an honest conversation about what they've labeled as racism. Conservatives should reflect on all the statements they have neglected to call racist that do deserve the term. Everyone should work to recognize that treating people equally and with respect is not about, and should not be motivated by, political correctness. It's a question of basic human decency.