THANKS TO HIS NIGHTLY CNBC SHOW Mad Money, Jim Cramer has become the chief cheerleader for the bull market, or what was the bull market until a few weeks ago. Last spring, he was giddily exhorting the Dow Jones Industrial Average toward 15,000, with no troubles in sight. Earlier this month, as the Dow tumbled in the direction of 13,000, he had an on-air meltdown, complete with screaming, sobs and predictions of financial doom. The clip quickly made the rounds on YouTube. Friday, after the Fed cut the discount rate, he said that the Dow's run to 14,500 had begun. With dramatic pronouncements like that, it's no wonder that more than 100,000 viewers tune in each weeknight for his antic mashup of sound effects, Streetwise advice and stock picks.