Whether they are dissembling, careless, or simply dumber than a bag of hammers, pandering politicians and pundits often misstate the facts. Given faulty premises they cannot possibly make a sound argument for whatever view they espouse. That's why Panderbear's motto is, "Check the facts, check the facts, check the facts."
The more insidious mode of pandering is to employ some combination of logical fallacies that renders conclusions specious even if the premises happen to be true. Most logical fallacies can be eliminated by simply asking yourself, do the facts presented really prove the claim? Common fallacies include ad hominem attack, appeal to authority or emotion or popularity, confusing cause and effect, false dilemma, guilt by association, slippery slope, and straw man.
Checking the facts and learning about common logical fallacies will arm you against bogus arguments by partisan politicians and biased cable news commentators while making your opinions more sound and your arguments more convincing.