We don't have time to do research projects on every topic, so probably most people live with imperfect short cuts when we want to figure out the answers to complicated or controversial questions.
One option is to try and figure out the consensus opinion and go with that. That's a good first order approximation. Another is to try and look at track records. That plays a big role for me.
The right really turned me off for the first time with the Iraq WMD failures. Not that the left didn't think Saddam had WMD. But the right was loudly touting conclusions based on bad evidence. The experts on the right in my view had a preferred conclusion and it overrode their ability to evaluate the evidence correctly.
The right did the same when it came to the motives of Islamic terrorists. It's obvious to me that Islamic terrorists are motivated by US violence. But on the right the view that they hate us because we're so great, which is obviously a preferred view since it strokes the ego, has a major foothold. The right has a powerful ability to allow their preferred conclusions to blind them to what in my view are obvious errors.
When Reagan raised taxes the right predicted dire economic consequences. The same happened when Clinton raised taxes. Those predictions were quite wrong. The right predicted that the Bush tax cuts would lead to prosperity and growth. What we actually have is just about the worst economic performance since the Great Depression in the wake of Bush's economic policies.
These things matter a great deal to me. It impresses me when a study shows that Paul Krugman is the top prognosticator, and Cal Thomas the worst. These things are not easy and you wouldn't expect even the smartest person to be right all the time. You can't anticipate some things that can effect predictions.
But probably his evaluation of this debt ceiling limit deal is worth considering. The Republicans pretty much got everything they wanted. No tax increases, massive cuts in entitlement spending. This in the middle of a terrible economic down turn with 9% unemployment. Here's Krugman on This Week(watch Part 2 here). He's expecting continued extremely high unemployment through the end of next year. He doesn't add this, but I suppose that's not going to bode well for Obama's re-election.
And I tend to think that's a good thing. The guy right flanks even Republican voters. That's been true for war, health care, and now taxes/entitlement spending. And lest you think this is about Obama being just unable to overcome Republican pressure, read Greenwald. Same old thing. If there's no price to be paid for a Democratic President when he acts like an extremist Republican, then why shouldn't everybody act like an extremist Republican.