OK, let me get this out first. Do I think it's still tough being an African-American? Absolutely. I'm not naive. Things aren't nearly as troublesome for American blacks as they were, say, back in the 1940s and '50s. But there are sure plenty of prejudices and other barriers, mostly economic, that remain for people in the United States who happen to enter the world with certain skin pigmentations. Heartbreaking and absurd, yes, but true.

And yet, just as Barack Obama's presidential campaign has (again) brought racial prejudice to the fore of American consciousness, so, too, has it displayed that race isn't the only baseline for bias and discrimination.

John McCain is learning about another bias -- that against older Americans. Oh, how he's learning about it. The release of his medical records has been like feeding time at the zoo among much media.

Perhaps most telling is many press accounts about the records, after they make clear the judgment of physicians that McCain is healthy, then go on to drop ominous hints about his skin cancer recurring, or other possible ailments that might hinder his performance if elected president.

One analyst even "reassured" us that McCain almost surely suffers from no psychological affliction -- no "reprogramming," among other things -- from his days of internment in a North Vietnamese prison camp. Unbelievable.

Then there's gender discrimination. Hillary Clinton is the poster woman for that one. Those folks are crazy who think the old boys of the Democratic Party aren't rejoicing over her defeat, and over her latest gaffe, when she offered Robert Kennedy's 1968 assassination as one key example of how presidential races can turn unexpectedly.

Polling numbers tell us that even women who are under 45 seem to care little about supporting a woman for the Democratic nomination.

"Well," you might ask, "why should a woman vote for a woman just because she's a woman?" Good question. But explain then why the same question isn't being asked of black voters following the exit polls that show nearly 90 percent so far having voted for Barack Obama in Democratic primaries.

I know the answer. Blacks are a minority that has suffered directly and at times purposely because of their race -- forced to use separate public bathrooms, as just one symbolic example. Anyone whose family or ancestors have been treated as second class people can rightly, perhaps righteously, feel an upwelling of pride at the thought of a black becoming president.

There's another bias in this country -- regional bias. Though it's become less fashionable to say so out loud, many Americans still view the South as being knee-jerk racist, not to mention generally backward and unsophisticated. Southern accents still get plenty of good ribbing. After all, they don't call former President Clinton "President Bubba" for nothing. Continued...