Several students in the film are explicitly referred to as Irish, including one total psychopath, a sadistic bigot named Artie West. Eventually, the entire class grows weary of West, but he will not go down without a fight. So, he grabs an American flag and its pole and turns it into a weapon, attempting to stab anyone who comes near him.

The message is clear — bigotry is anti-American, and bigots turn what is beautiful about America into something ugly. The fact that the bigot is Irish American is an uncomfortable mix of sociology and stereotype.

Fast forward two decades and, in Irish South Boston, life imitated art. It was the height of the infamous busing controversy, during which the courts ruled that African American students should be bussed to schools in heavily Irish South Boston to promote integration.

During one protest, photographer Stanley Forman snapped an unforgettable image, a “Southie” protester brandishing a flag, moving to attack an African American.

That photo is the subject of a new book by Louis P. Masur entitled The Soiling of Old Glory: The Story of a Photograph that Shocked America.

In a review this week for Salon.com, Louis Bayard (just as the makers of Blackboard Jungle did) links the Irish to the racial tension in South Boston.

“The busing struggle was just the flashpoint that lit up ancient divisions. Look in the background of Forman’s picture, and you’ll see a swell of flannel shirts and Celtics jackets — the warrior garb of the Southies, white Irish Catholic working-class folks who, in Masur’s words, had ‘watched their economic status decline, felt deep ties to their local community, disdained the riots that had engulfed the nation (Watts, Newark, Detroit, even Roxbury), and resented all the effort on behalf of black rights.’”

Going back to the Draft Riots of the 1860s, the Irish have been part of ugly racial tensions. But, at least this is all in the past, right?

Not quite.

A slew of commentators are suddenly fascinated by the voting patterns of “white Catholics,” of which the Irish represent a large chunk. They are noting that Barack Obama has performed very poorly with this group.

Why? Michael Sean Winters bluntly asked in America magazine, “Are Catholics racist?” He then added, “Is there something distinctive about Catholics that make them unlikely to vote for Obama?”

After noting some progressive positions taken by the church, Winters then writes, “The principal reason for Catholic hostility to blacks, however, lay not in history but in ethnicity and the way that a certain tribalism has characterized American Catholi-cism.”

I don’t have a huge problem with Winters’ analysis -– though one suspects if another religious or ethnic group were labeled “tribal,” there would be some howls of insensitivity.

Anyway, as the current issue of New York magazine asks, why does this matter?

“Because for more than 40 years, the ability to capture working-stiff whites has been the sine qua non for Democratic success at the presidential level. That Obama is having big trouble with such voters would be bad enough by itself,” reports the magazine.

“But making matters worse is his abysmal recent performance among white Catholics — he claimed 34% of their vote in Ohio and 29% in Pennsylvania. In the past two elections, according to Brookings Institution scholar Bill Galston, among others, white Catholics have emerged as perhaps the most pivotal constituency in the electorate.”

In fairness, I have to credit these analyses for being relatively even-handed. Still, the overall message here seems to be that the Irish are prized, but also racist.

It might help if people looked at this the other way: Why is Hillary performing so well with Catholics, members of a (supposedly) patriarchal church?

That’s a topic for another time. At least no one is accusing Irish voters of brandishing flags as weapons. Well, not yet anyway.

(Contact Tom at tomdeignan@earthlink.net.)