Are we experiencing the most immature, juvenile, childish government ever?

Or have all governments been like this and I just didn’t notice?

The first instance that comes to mind was when newly elected Barack Obama was addressing Congress (I think it was Congress) and someone interrupted what he was saying by screaming, “LIAR!” from the back of the room. It didn’t even have anything to do with what Obama was saying at the moment. The guy was just calling names.
Obama leveled a look at him that told him clearly he was WAY out of line and behaving badly and he’d better sit down and mind his manners or he was going to put him in time out!

There have been many instances since then, but then today, this caught my attention.
Did the Republicans really have a poster made up before hand going “Liar liar pants on fire!”?
Why didn’t they also get posters that say “Nanny nanny poo poo! I know I am but what are you?”

What happened to decorum? What happened to class and grace? Or are we stuck forever with a bunch of playground bullies?

Or is this behavior due to a “trickle down effect” that actually trickles down (unlike economic trickle down.)