In a recent interview with Republican presidential front-runner Donald Trump, CNN's Jake Tapper said, "I would just ask, as a fellow American, if you could consider whether or not dialing down the temperature — trying to bring down the temperature — might be a healthier thing both for your campaign and for the nation at large." And PBS' Tavis Smiley — who once said Ronald Reagan "tortured" blacks — calls Trump a "religious and racial arsonist."

If only Tapper and Smiley would urge liberals and Democrats to adhere to the same level of civility and probity they demand of Trump. For example:

Vice President Joe Biden, during a 2012 campaign speech, told a predominantly black audience in Danville, Virginia, that Republican candidate Mitt Romney was "going to put y'all back in chains."

Democratic National Committee Chairwoman Debbie Wasserman Schultz, in 2011, said Republicans "want to literally drag us all the way back to Jim Crow laws." She further compared the push for voter ID to the imposition of a poll tax, a notorious relic of the Jim Crow South.

Donna Brazile, now a political commentator on CNN, was the campaign manager of Al Gore's 2000 presidential bid and served as interim chairwoman of the DNC. While Gore's campaign chief, she said the Republican Party has a "white boy attitude," which means, "'I must exclude, denigrate and leave behind.' They don't see it or think about it. It's a culture."

Hillary Clinton, in a 2006 speech before a predominantly black audience, said, "When you look at the way the House of Representatives has been run, it has been run like a plantation — and you know what I'm talking about."

Claire McCaskill, now a senator from Missouri, said that in the aftermath of Hurricane Katrina, "George Bush let people die on rooftops in New Orleans because they were poor and because they were black."

Howard Dean, while chairman of the DNC in 2005, said the contest between Democrats and Republicans was "a struggle of good and evil. And we're the good." He has also called Republicans "evil," "corrupt" and "brain-dead." Julian Bond, then the chairman of the NAACP, the nation's oldest civil rights organization, said of Republicans in 2006: "Their idea of equal rights is the American flag and the confederate swastika flying side-by-side." And in 2001, he said of President George W. Bush's new administration: "They selected nominees from the Taliban wing of American politics, appeased the wretched appetites of the extreme right wing and chose cabinet officials whose devotion to the Confederacy is nearly canine in its uncritical affection."

George Soros, the left-wing billionaire donor, said that George W. Bush's White House displayed the "supremacist ideology of Nazi Germany." Soros said, "When I hear Bush say, 'You're either with us or against us,' it reminds me of the Germans." Soros later said: "The Bush administration and the Nazi and communist regimes all engaged in the politics of fear. ... Indeed, the Bush administration has been able to improve on the techniques used by the Nazi and communist propaganda machines."

Charles Rangel, long-time congressman from Harlem and founding member of the Congressional Black Caucus, called George W. Bush "our Bull Connor" — referring to the former public superintendent of safety in Birmingham, Alabama, who sicced dogs and turned water hoses on black-and-white civil rights protesters. About the GOP's Contract with America, Rangel said, "Hitler wasn't even talking about doing these things."

Al Gore said then-President George W. Bush's "executive branch has made it a practice to try and control and intimidate news organizations, from PBS to CBS to Newsweek. ... And every day, they unleash squadrons of digital brown shirts to harass and hector any journalist who is critical of the president."

President Barack Obama said: "The legacy of slavery, Jim Crow, discrimination in almost every institution of our lives — you know, that casts a long shadow and that's still part of our DNA that's passed on. We're not cured of it. Racism — we are not cured of it."

Former President Jimmy Carter explained the opposition to Obamacare this way: "I think an overwhelming portion of the intensely demonstrated animosity toward President Barack Obama is based on the fact that he is a black man, that he's African-American. ... Racism ... still exists, and I think it's bubbled up to the surface because of a belief among many white people, not just in the South but around the country, that African-Americans are not qualified to lead this great country."

That statements like this escape the condemnation that they deserve once again exposes double standards and selective outrage.

The pass enjoyed by the left does not excuse careless and irresponsible statements made by Donald Trump. But let us condemn, with at least the same degree of fervor, the nasty, vicious, divisive race-card hustling and the "us against the evil opposition" rhetoric routinely, and all too casually, employed by the left.

Is that too much to ask?

Larry Elder is a best-selling author and radio talk-show host. To find out more about Larry Elder, or become an "Elderado," visit www.LarryElder.com. Follow Larry on Twitter @larryelder. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.