Why are Americans uninformed about issues in a campaign?

Many people are discouraged about politics in general, because all politicians lie, all the time. They make campaign promises that they know they cannot keep (and wouldn't, even if they could) and play off one interest group with another. They promise both sides that he'll vote THEIR way, and depend on Group A not learning what he has promised to Group B. The internet is making life tough for politicians, because it is becoming easy to learn about the secret promises made to each group.

The "Patient Protection and Affordable Care Act" (PPACA, or ACA), otherwise known as "Obamacare", may be the prime example. Before he ran for President, Obama was quite clear that his goal would be "single-payer" or "socialized" medicine, a system which has failed everywhere it has been implemented. As President, campaigning for the ACA, Obama promised on dozens of occasions "It you like your health plan, you can keep your health plan. If you like your doctor, you can keep your doctor. Period." These turned out to be lies.

One of the architects of Obamacare, Jonathan Gruber, said several times (while being recorded!) that Obamacare had been possible only because Americans were stupid enough to believe the campaign promises.