1. Congress critters DO pay taxes on their salaries. So they do pay for it just as we pay for Medicare or would like to pay for Single-Payer.
2. What makes you naive is that you dismiss the actual truth of the matter. There are now, and ever have been, elected representatives from all parties that act in the best interest of the nation(quite likely outnumbered at this point in time). Your personal inability to cut through the partisan propaganda and take measure of them leads you to endorse platitudes such as the one we are unfortunately discussing now.
3. It's a much less strenuous course in life to yell "Throw the bums out", than it is to grind the data.