In theory, conservative philosophy is one that fundamentally resists radical change. Liberal philosophy embraces it. As long as there are two parties espousing those respective philosophies, and those two parties are relatively evenly matched, the resulting struggle can uncover a sane, stable path forward, balanced between the two.
Unfortunately, the current version of the Republican Party isn't particularly conservative, and the current version of the Democratic Party hasn't been particularly liberal. The latter, at least, is changing, thanks to grassroots efforts from the likes of the Great Orange Satan, but there are still a lot of entrenched corporate Dems whose guiding philosophy is merely to gain and maintain power for themselves, regardless of which teat they need to suckle at to get it.
As for the Pubs... ugh. The neo-con philosophy has about as much to do with conservatism as the '60s definition of 'liberal' has to do with classic liberal economics, and what Sully calls the Christianist base isn't interested in a conservative path forward; they actually want a path headed backwards.
The Dems are still salvageable. I don't think the Pubs are.