Proof that American political lives have second acts was provided on the stage of the Kimmel Center on Tuesday when Mark B. Cohen, 68, was sworn in for a 10-year term as a Common Pleas Court judge.

A Democrat from Northeast Philly, Cohen is a refugee from Harrisburg, where he served in the state House from 1974 to 2016. During his 42-year run, he earned the sobriquet "king of perks" (hat tip to my colleague John Baer).

Why that nickname? In a second.

Mark Cohen is an example of Philadelphia dynastic politics, his political aspirations boosted by the reputation of his hard-working father. Mark's younger brother Denis, 66, is a Common Pleas Court judge, and their sister Sherrie, 62, has run for City Council.

I was friendly with patriarch David Cohen, the venerable, uber-liberal City Council member who was an indefatigable champion of everyday people, assisted by his peppery wife, Florence.

Neither of them would be found feathering their nest.

Their son, on the other hand, has been accused of racking up expenses that would shame a Kardashian.

In 1990 it was reported that Mark Cohen tacked on more than $100,000 in expenses (including $11,000 for airline tickets) to his $80,000-plus House salary.

In 2004-05, Cohen billed the state for $28,200 for more than 800 books, claiming he needed them to become a better rep.

Where could he find time to read so many books? Maybe on flights between Philadelphia and Harrisburg, also billed to the state. Press exposure shamed Cohen to cut back his book club and to switch from plane to train for the 100-mile trek between his home and Harrisburg.

He shamelessly billed the state — that is, you — for "work" he supposedly did on Christmas; Easter; Labor Day; even Yom Kippur, the holiest Jewish high holy day (when work is forbidden). He had other questionable expenses, but my space is limited.

This pork was made possible because the state offers lawmakers per-diems of up to $185 a day — tax-free expense payments that require no receipt. Free for the taking, as long as it's "legislative business."

As Baer wrote in 2016, Cohen "justified expenses on grounds he was constantly busy. But he found time to get an M.B.A. and a law degree while serving full-time in office."

Over the years, Cohen defended his wild spending by saying he put in a lot of time in Harrisburg and was one of the hardest workers in the House. He is particularly proud of his leadership in legalizing medical marijuana, he told me Wednesday.

Given all the criticism, I asked the new judge, elected Nov. 7, if he had any regrets about those expenses. "There was no dispute about the legitimacy of the expenses, only the totality of the expenses," he said, which amounts to: no regrets.

Cohen lost his House seat in the 2016 Democratic primary to Jared Solomon, who was supported, Cohen said derisively, by business interests, "many insurance companies, large corporate law firms, and some conservative labor unions."

Now out of the House, Cohen will be drawing a pension of around $100,000 a year. His judicial salary is $178,868 — and that will further grow his pension.

Although his new salary is about twice what he earned as a state rep, he has a big handicap: This job doesn't come with an expense account.

On the other hand, if he threatens to throw the book at someone, he's got the library to do it.