The Irish are storming New York’s theater world. And they may not know it, but they are providing some insight into just why so many American voters seem scared out of their minds.

For generations, high schoolers have read the stilted language of Arthur Miller’s play The Crucible. Now it’s back on Broadway, starring Irish Academy Award nominee Saoirse Ronan as well as Irish actor Ciaran Hinds. The play is set way back in the American colonial times of the 1600s.

But Miller famously had a modern American problem on his mind when he wrote the play in the 1950s: the anti-Communist witch hunts of the 1950s. The most notorious figure to emerge from those dark times was one of the most infamous Irish Catholics in American political history: Wisconsin senator Joseph McCarthy.

Another theatrical production opening this week, also heavy on Irish flavor, is the thoroughly-entertaining Cagney: The Musical. Billed as a show about “Hollywood’s tough guy in tap shoes,” the show stars Robert Creighton in the title role.

What else could he play? He bears a striking resemblance to the Public Enemy star (including the diminutive stature) and can strike a boxing stance as well as tap like his feet are on fire.

But the Cagney show also offers striking insights into the actor’s complicated life -- and shines a light on some of our enduring political problems.

First, there is Cagney’s poverty-stricken youth. James Francis Cagney Jr. was one of seven kids growing up on the Lower East Side. (The show fudges the truth a bit. Cagney’s mother, in the show, speaks in a theatrical Irish brogue though it was actually Cagney’s father who was Irish; his mother was Norwegian.)

Young James tries to do his best to help the family out, but his employees are always looking to cut corners and squeeze workers for every last dollar. Sound familiar? Why else do you think New York just joined several others states in raising the minimum wage to $15 an hour?

Such memories stuck with Cagney even when he became a Hollywood big shot. The show notes that while he was making his early gangster pictures -- and making studio big-wig Jack Warner boatloads of money -- the star of the show was not seeing very much money himself.

Not for nothing did Cagney become a force in Hollywood union politics, teaming up with another actor of Irish descent, Ronald Reagan, on a number of labor causes.

But, as Cagney: The Musical also notes, Cagney himself got swept up in the same anti-Communist hysteria that The Crucible highlights. And this was even before the emergence of Joseph McCarthy.

There were whispers for years that Cagney was a Commie sympathizer. He had donated money to striking workers and also lent his name to the “Free Tom Mooney” movement, which called for the release from prison of an activist (and son of Irish immigrants) accused of a deadly bombing.

Cagney was called before the House un-American Activities Committee in 1940. Chairman Martin Dies cleared Cagney, who was not found to have any Communist ties. But, of course, Cagney was one of the lucky ones.

In the end, when you look at Cagney and The Crucible you can’t help but think of our current, equally-paranoid times. Then, as now, there is an anger out in America that is leading to some scary possibilities.

But, before we make too much of a martyr out of Jimmy Cagney, it must be pointed out that he -- again, like Reagan -- changed his views quite a bit as the years went on. You won’t see this in Cagney: The Musical. But the legendary actor would go on to describe himself as an unapologetic “arch-Conservative.”

In his autobiography, Cagney rails against “the undisciplined elements in our country” and “liberal attitudes towards the young” and (seriously) “those functionless creature, the hippies.”

Who delivered the eulogy at Cagney’s 1986 funeral, but Mr. Ronald Reagan.

How about that? Jimmy Cagney, union man, probably would have voted for Donald Trump.