Change my mind: the RW has been losing because of its "principles".

Yes, because electing RINOs and welcoming in ideological refugees has worked so well for the RW.

The other side has none at all and yet it always wins.

Their principles are whatever the media tells them and they stick to them, no matter how irrational or illogical it is. If they didn't stick to those principles, they wouldn't have advanced their agenda and turned America into a shithole country.