You'd think explicitly political think tanks wouldn't change much in politics. The only people that listen to conservative think tanks are conservative. The only people that listen to liberal think tanks are liberal. So maybe they help fill in policy details, but not much else. Right?
I'm not as sure.
Let's say you're Justin Amash, Republican representative. You're pretty conservative, remarkably thoughtful, and (because having thoughts puts a target on your back) you've faced some ludicrously brutal primaries.
If you just want to be a party mouthpiece, that's pretty easy. If you want to pander to extremists to win the primary, that's pretty easy too. But what if you want something else – what if you want to (and I don't want to alarm you) do something you think is right?
Well, sometimes that won't be the pandering choice. And when people think you did something they don't like, you need a way to pitch those members of your own party so you don't get punished in the primary for having actual principles or goals. You're Justin Amash, libertarian-leaning Republican, so you say, "Yeah, that's a good question, I voted that way based on an analysis the conservative Cato Institute did, they think it's a pretty bad policy and they persuaded me, let's discuss this..."
It isn't just some nerds, it's conservative nerds. Everyone in the conversation is on the same team. And who knows, you might actually persuade some people. At the very least, you'll seem like a predictable and solid representative of the party, which doesn't hurt at all in primaries.
So explicitly political think tanks can, at the margin, get more apolitical technocracy, people doing things that work instead of being political hacks or extreme zealots.
It's worth making explicit something I've noticed – the renowned think tanks on both sides of the aisle are usually quite meticulous. Almost all of their bias comes in the form of which questions they ask and what they think is important. They aren't just making things up, they're doing research to solve issues important to them – the issues are political but the solutions are whatever they honestly think works best. Obviously, without the scholarship, this argument falls apart, which is why we should all be skeptical of thought-leaders in our own ideological corner.