Does Congress need more or fewer pure ideologues?

We have a growing number of politicians now, particularly in the US House of Representatives, that care more about their ideological principles than anything else, and that seems to include the future of the USA. But the hyper-partisanship we see in Congress is not reflective of the American people, as this TED talk by Adam Davidson, co-host of Planet Money explains, most Americans are centrists.

Closed primaries are a big part of what creates the partisan gridlock problem. While over 40% of the US public are independents, not registered to either party, Republican primaries in particular are closed. Only registered Republicans are allowed to vote in the primary, and only the most partisan of those typically turn out for primaries, which are notoriously low-participation elections.

Add to that the gerrymandering done in redistricting, and you have a system rigged to become ever more partisan and hate driven. The primary system is rigged to select the most wildly partisan candidate, and the actual election system is rigged to make sure the rigging party’s candidate wins, no matter how distorted and far from mainstream public opinion their ideas may be.

Instead of electing a group of pragmatists willing to go where the evidence takes them, you get ever increasing ideological purity where facts are irrelevant, only ideological beliefs matter. You get people who firmly believe their ideology is perfect, and any deviation from it, any compromise, will cause the sky to fall.

Is this increasing partisanship and ideological purity a good thing? If not, what should we do to reshape the system so it no longer encourages it?