The term “rot in prison” was assigned a poster boy this week by an Arizona judge.

Dennis Mahon, among the nation’s most stalwart white supremacists, received a 40-year sentence in a case where a pipe bomb exploded in the hands of an African-American diversity director in Scottsdale. Mahon started here, honing his hatred 30 years ago in the Kansas City area. Given that Mahon’s defense portrayed the 61-year-old as an aging alcoholic who guzzles Everclear, it’s doubtful there will be any centenarian celebrations. He’ll die in prison.

Don Logan was the intended victim of the 2004 bombing. He opened the parcel. Surgeons had to piece his hand and portions of his arm back together.

According to Mahon’s own bragging, the bombing is just the only thing he was ever caught at and convicted of doing. His actions spanned decades, as he cultivated international connections and aligned himself with the most violent people within such movements, according to Leonard Zeskind, a Kansas City area expert on white nationalist political and social movements.

Indeed, much of Mahon’s life could dramatize how the Klan turned to para-military, anti-government movements, mixed with Aryan sects, tapped into Neo-Nazism and now are attempting to gain credibility by testing the waters with mainstream, conservative causes.

Kansas City met Mahon in 1987 as a Klansman. That’s also when he traveled to Germany.

Later, after moving to Oklahoma, he’d be investigated for connections to Oklahoma City bomber Timothy McVeigh, although nothing was ever substantiated.

Mahon’s ties with anti-government extremists in southern Missouri played a role in his Arizona trial. That’s where his cohorts would learn about making pipe bombs.

Federal agents spent five years building the case. That’s patience well placed.

Perhaps the arc of Mahon’s racist “career” needed to be this drawn out before the law caught up with him.

He can’t escape how the nation’s attitudes about race have changed dramatically. Obviously, there are still problems.

But Mahon is entering prison after the nation elected a bi-racial man to the White House. Americans are increasingly astute at understanding the impact of class on race. And recent efforts by people of Mahon’s ilk to gain a veneer of respectability by joining conservative organizations have been called out.

There are fewer places for the Dennis Mahons of the nation to hide.

At sentencing, the judge noted that the bombing went beyond one racial target. Mahon, the judge said, “acted to promote racial discord.”

That’s been Mahon’s life. And now, he’s finally going to answer for it.