"the crazy statements"? You don't have very competent news sources, do you?
Lots of crazy liberals want mankind living like it's the stone-age to save the planet. Lots of crazy liberals support eugenics with a new modern-day presentation. And plenty of other radical communist, authoritarian doctrine.
I don't hold these views against socialists/communists/progressives/democrats/"the left" in general. I do no such thing.
I make fun of ignorant hicks who think they're socialist academics all the time, but I don't do it in such a dishonest way. Sure I'm mean, but I don't base arguments on meanness. Most people don't hold eugenicists and eco-terrorists against Democrats and American "liberals."
This guy is a representative, so it's legitimate news that he said it and it's a legitimate reaction to want his party to call for him to abandon his race. If they don't go through with their threats to withdraw funding, I'll certainly accept that as substantiation of Republicans being crazy. That's what's lacking here: Any substantiation that this whacko represents conservatives any more than whackos on the left represent liberals.
There are plenty of crazy liberals, but they don't receive this attention as if they represent liberal views as you claim here. Barack Obama, as a state senator, supported legislation allowing doctors to deny babies born alive after failed abortions medical care. I think that's pretty crazy, for a people who like to think themselves civilized and compassionate. But things this crazy--and much worse--are ignored regularly and never attributed to the general consensus of liberals in America.
I think your claim that "both sides" do it is pretty baseless, generally speaking. I think it's irrational and dishonest to pretend, either way--by either side--and not legitimate political discourse. And I think it's especially bizarre to engage in this dishonest, irrational discourse, claiming "the other side does it too," when they usually don't--certainly not to this extent.
And I'm not a "conservative" so you can kiss my arse. I don't like irrational hypocrisy by any side, even if they're both wrong. 
[I wish I could obey forum rules]