Well, not quite stop them, but here are two ways to avoid them.
1) Don't watch TV. Read lots of newspapers and magazines instead.
2) OK, you don't want to give up sports, reality shows, and Comedy Central. Then try these simple steps each time a political ad comes on the screen.
a) Close your eyes
b) Put your hands over your ears
c) Count to 60
With these three simple steps you won't have missed anything meaningful.
Remember also that political ads are designed not to get you to vote for a candidate, but to get you discouraged about the other candidate and not even vote. It seemed to work very well in New York's Ninth Congressional District in 2011. The Republican candidate won despite a 3 to 1 Democratic registration.
So, get even yourself and be sure to vote. Remember that the biggest spender is not always the winner. Think Meg Whitman who outspent Jerry Brown by a wide margin for governor of California and lost by a wide margin.
