We got the main band members heading into LAX Monday, and you bet your ass we asked them about their lyrical switch-up on "American Idiot" 2 weeks ago during their Dick Clark 'New Year’s Rockin’ Eve' gig ... which saw them change the word "redneck" for "MAGA."

Basically, Billie sang ... "I'm not part of a MAGA agenda" instead of the OG line, and it triggered the hell out of Trump supporters, who were dragging the GD crew online.

Now, all these days later ... we asked the boys about it, including Billie Joe Armstrong -- who says it was par for the course for the MAGA people ... likening it all to pearl clutching. When we asked if BJA had a message for all the people he pissed off ... he blew 'em a kiss.

Same vibe from Green Day's longtime bassist Mike Dirnt and OG drummer Tré Cool -- who basically echoed Billie, saying they did what they did ... and have no regrets about it either.

Now, on the question of whether they think America, at large, has gotten dumber since they first put out the song way back in 2004 ... well, they had some interesting responses.

Take a listen for yourself ... sounds like the fellas think the US of A might be a lil' stupider today than they were during the Bush era. More than just that though ... we're divided.