In a fascinating long-form interview with late night talk show host Conan O’Brien published online Friday, New York Times pollster wiz Nate Silver said -- while wearing a Cookie Monster T-shirt -- that a "rational" Republican Party should take up drug legalization, among other issues, if it hopes to stay relevant.

Around 22 minutes into Conan's interview, he asked Silver what advice he would give the Republican Party going forward in 2016. Silver said that "a rational political party" would modernize its views on issues like same sex marriage, immigration and drug legalization.

"Yes, of course you're going to shift to the center a little bit on immigration and gay marriage, which are two issues where the younger cohort feel much differently than than older voters do," Silver said. "Right? Maybe drug legalization and a few other issues like that. That's what a rational political party would do."

He added that even though President Barack Obama won a decisive victory over former Massachusetts Gov. Mitt Romney (R), the Republican candidate still got 47 percent of the vote. "It's not that far from 50 percent, So there is a rational road forward for the Republican Party, and yeah, of course it's going to involve moderating on some select issues and being a little bit more inclusive. If they don't do that, then they could be in the wilderness for some period of time."

"I was just enjoying that you were advocating drug legalization while you were wearing a Cookie Monster T-shirt," Conan replied. "I just enjoy that."

For the record, Silver wrote in 2009 that opinion trends show that marijuana legalization appears inevitable, although he cautioned that a "supermajority" (60 percent or more) of the American public would have to come around before the federal government takes it seriously.

The polling firm Gallup said in October 2011 that 50 percent of Americans favor legalizing marijuana, up more than 4 percent from just one year prior.

This video is from, published Friday, December 7, 2012.