The "Real Time with Bill Maher" host said the state of California was proof that doing the reverse -- raising taxes on the most wealthy -- could actually lead to a booming economy.

The comedian hailed The Golden State, where "Democrats from governor on down control every office and voting body," was now heading toward becoming the fifth largest economy in the world.

"Thanks, England," he quipped, in reference to Britain's plunge in the global financial ranks following its decision to exit the European Union, known as a "Brexit."

#NewRule: If Republicans are going to keep calling states “laboratories of democracy,” they have to look at the results from the lab. #RTWBM — Real Time (@RealTimers) July 2, 2016

Meanwhile, in Republican-run states like Kansas and Louisiana, Maher said the "old trickle down theory of cutting taxes on the rich and they'll do their thing" was "failing catastrophically." It's time for the GOP to try something different, he added.

"If Republicans are going to keep calling states 'laboratories of democracy,' they have to start looking at the results from the lab," Maher said.

"After Arnold (Schwarzenegger) left office, we eliminated what scientists would call variables — in this case, the Republicans," he quipped. With the Democrats in firm control in California, Maher said it allowed the possibility to "really study what happens when liberal policies are tried unimpeded."

"And the only thing I have to say to Republicans about that is: scoreboard, bitches," he added.

Check it out in the clip above.