This leaves the liberal Rep. Mark Udall ...
The Mark Udall is not a moderate scoreboard:
reliably left wing 5
We started this scoreboard when we noticed that liberal blogs and the msm were routinely calling Mark Udall a "liberal," "reliably left wing," and even "extremist." We do not count comments from conservative blogs and we didn't count a comment on a liberal show by a conservative politician. Those who would like to check our methodology can follow the bread crumbs backwards