In this year's contest for the Democratic presidential nomination, Barack Obama has been taken to school by Hillary Clinton and the Republican right wing. The New York senator and her GOP allies are giving him lessons in politics' dark side. Whether he's learning anything remains to be seen.

Obama's experience, however, should be instructive for young people drawn to politics by his candidacy, especially those thinking of following in his footsteps.

Consider what Hillary & Co. have taught thus far:

Lesson One: The enemy of my enemy is my friend.

A story told once before: In 1960, when I was a junior in college, Hubert Humphrey visited Howard University during his campaign in the DC Democratic primary. He was also running against John F. Kennedy in the West Virginia primary, where the Massachusetts senator's Catholicism was being assailed.

A government major, I asked Humphrey how he felt about the attacks against Kennedy's faith. Humphrey, not missing a beat, said that although he was seeking victory, he didn't want to win with anti-Catholic votes. To Humphrey, an enemy of his friend was his enemy, too.

Not so with today's Clinton-conservative lash-up.

Granted, Hillary Clinton has philosophical differences with the putative Republican presidential nominee, John McCain; far-right-wingers Pat Buchanan and Rush Limbaugh; and the conservative talking heads on Fox TV. But they and Clinton have a common enemy: Obama. Their allegiance to the goal of bringing him down makes them compatriots.

Qualifications

To discredit Obama, Clinton plugs McCain's commander-in-chief qualifications. She and McCain, working from similar talking points, do a tag-team number on Obama, labelling the Democratic Party front-runner "out of touch" and "elitist."

Buchanan, who proclaims that "reverse discrimination is pandemic," goes into overtime branding Obama as a left-wing zealot while praising Clinton as a paragon of Middle American virtues.

Reminder, young hopefuls: There's no telling what some folks will do to get ahead.

Lesson Two: Resort to McCarthyism.

Discredit your opponent by associating him or her with someone who is strongly disliked or deemed disreputable.

Case in point: Link Obama with controversial figures to call into question his fitness for the presidency. Senator Joe McCarthy did it by impugning the patriotism of innocent Americans. It worked for him - for a while.

Guilt by association is being tried again.

Lesson Three: Getting too big for your britches is costly.

Frederick Douglass, former slave, abolitionist and human rights champion, could have told Obama that there would be days like this.

It's one thing to have a great speaking voice and a commanding presence, as did Douglass - and, likewise, Obama. It's quite another matter to think you have something important to say. Worse yet, to tell yourself you can be a leader, not just a loyal spear carrier.

Douglass found that out.

He had to prove he once was chattel, and he was discouraged from stepping up and out of his place.

Remember, young folks, there's a price to be paid for appearing uppity.

It could even cost you the presidency.