Why has the GOP been getting less popular since unleaded gasoline was introduced?

Because the people whose brains were damaged by lead have been dying off and the people born since then are thinking more clearly and are more liberal.

How is it "less popular"? In 1995, there was a Republican House and Republican Senate for the first time in about 60 years. And of the 12 Congresses since then, 7 had GOP in control of both chambers, 2 had Democrats in control of both chambers, and 3 were mixed. Additionally, Republicans have in that time also gained control of more state legislatures and more state governorships.

If that's "less popular", then being popular must really suck.

Pop culture

Surely you can ask a more idiotic question, I believe in you

(for a party that claims to be "educated"...)

Sad

House, Senate, White House, 69 of 99 state legislative chambers, 33 governorships, and a conservative Supreme Court.

Yup, it's looking bad for the Republicans (sarcasm).

And yet the GOP holds more power in the US as a whole than at any point in modern history..

Reality sort of contradicts your assertion

They give off plenty of gas.

I'm sorry but the GOP has been doing nothing but winning of late.