The 2012 election campaign has barely begun, but broadcasters can expect to see “an unprecedented frenzy of political advertising,” with total sales running as much as 18% higher than the $2.3 billion spent in 2010, Moody’s Investors Service says in a report today. The U.S. Supreme Court has tossed out spending caps for corporations and unions, making this the first presidential election in more than a decade without such limits, the research firm says. “The campaign frenzy will get some of its oxygen from high-visibility headline issues, including a weak domestic economy, high unemployment and a continued slump in real estate,” Moody’s says. “Control of Congress is also in close contention.” Republicans “may possibly view the Senate to be within their reach in 2012.”

Others also say that the Republican presidential candidate won’t make the same tactical mistake John McCain did in 2008: He accepted federal funds for his campaign, which included caps on his ability to spend. That put him at a tactical disadvantage to Barack Obama, who didn’t take federal cash. “It would be a shock if the Republican nominee (in 2012) took federal funds,” says Ken Goldstein, president of the Campaign Media Analysis Group. Although he doesn’t have a precise forecast yet, he expects to see “more of everything” in 2012.

Moody’s says cash will flood into battleground states for the presidential race including Florida, Pennsylvania, Ohio and Missouri. The firm also expects to see tight U.S. Senate races in Virginia, Massachusetts and Nevada. There could be hard-fought ballot issues in Wisconsin, New York and Ohio involving union collective bargaining rights. In addition, voters may weigh in on budget matters in California and Oregon.

All ad-driven media will benefit from the increased spending. But “television broadcasters still attract more ads than any other media,” Moody’s says. The firm says that the political cash will help to generate record revenues in 2012 for Gray Television, LIN Television, Nexstar and Sinclair Broadcasting Group. But the bonanza will be short-lived. In 2013 there’ll be just two gubernatorial races, in New Jersey and Virginia. Moody’s says that if stations use their 2012 cash to pay down debt, it could be “a far better way to prepare for the future than waiting for another helpful ruling from the Supreme Court.”