The airwaves this weekend will be loaded with what one TV station manager calls a "tsunami" of midterm election advertising — most of it negative. It begs the question: Who is reaping a windfall from all of this cash? Chris Stern of Bloomberg News finds that the spending has been so bountiful that it has already bolstered the quarterly results of such station groups as Gannett, Belo Corp. and E.W. Scripps Co. With so many more races in play, it has both parties spending heavily in such markets as Rochester, Minn., where the general manager says they don’t have enough airtime to satisfy demand. The Campaign Media Analysis Group, which tracks such things, predicts a record $2 billion in spending this year, $300 million more than in 2004, when there was also a presidential election. Some station managers are raising prices. The general manager of an Albuquerque station tells Bloomberg, "We start them out at the top fixed rate, which nobody pays by the way, then we double it. It will triple in the final week."