At ballparks the crowd is encouraged by lighted signs to “Make Some Nosie!” At TV game shows and talk shows with a live audience, there used to be applause signs and an off-camera cheerleader to get the crowd to whoop it up on cue. How quaint. Lately such stage management is hardly required.

We have become a nation of boisterous yahoos who think every event requires their loud participation. The mere sight of a TV host provokes chants worthy of a Fuhrer (Stephen! Stephen!) The introduction of guests is often greeted by prolonged demonstrations, swooning cries from females for Hugh Jackman, whistles and the howls of beasts in heat for Scarlet Johansson. It cuts the need for creativity since a quarter of every show will be drowned out by the mob.

All of American life has inexorably been turning into reality TV. The audience decides who will win the tiara for the best dancer, singer, comic, bachelor or castaway. This sort of thing goes way back, of course, to Major Bowes and Roman gladiators. But now we are rating doctors and lawyers and plumbers and chefs on line.

Instead of the Good Housekeeping Seal of Approval or the results of Consumer Reports testing, or the expert opinion of experts, everything is rated by everybody. Actual knowledge or information carries no more weight than the whims of a chimp pounding a keyboard.

The electronic media are co-conspirators in this rule by means of crowd-sourced opinion. We no longer have political debates on the issues, but dueling polls. Donald Trump, a pure product of the alternative reality of TV, has turned his campaign into egomaniac Nuremberg rallies complete with storm troopers, scapegoats, grievances, grandiosity and throngs of acolytes repeating his punchlines which they have memorized from frequent repetition. Like a band’s greatest hits.

Actual televised debates used to be decorous snoozes of interest only to policy wonks and the kind of voter who decides the course of democracy on who he or she would like to have a beer with. A small live audience was permitted to applaud when the candidates were introduced and at the conclusion of the closing remarks.

Now the debates are held in huge halls and the crowd is an equal participant to the candidates. They scream encouragement, boo the hated opponent, and bray with glee when a put down is delivered. Often the groundlings are so loud they drown out the cast. And the overheated atmosphere encourages a descent by the candidates to harsher rhetoric, cruder generalizations, more vituperative exchanges and pandering one-upmanship.

We have now managed to turn almost all entertainment and politics into a cross between TV wrestling and an Alice Cooper concert. That may be fun when school’s out for summer and the crowd is deciding who’s the fairest in the land or which door the contestant should choose on “The Price is Right.” But it’s a hell of a way to run a democracy.

We are close to the day when the roar of the crowd will decide which country to invade, which minority to deport, whether to increase taxes to pay for Medicare and build roads or increase the national debt in order to give every American — “A Brand New Car!”