A report released Friday by the University of Wisconsin Advertising Project found Presidential candidates have spent $107 million on television advertising, although little has been spent in Super Tuesday"" states.
The report was compiled of data beginning on Jan. 27, and accounts for political advertising across the country in 90 percent of households with televisions.
U.S. Sen. Barack Obama, D-Ill., and U.S. Sen. Hillary Clinton, D-N.Y., spent nearly the same amount, with Obama spending only slightly more. Former U.S. Sen. John Edwards, D-N.C., spent only half that amount.
On the Republican side, former Massachusetts Gov. Mitt Romney spent as much as all his opponents combined. Romney spent four times as much as Sen. John McCain, R-Ariz., in Florida, though McCain beat Romney in the primary.
McCain spent less than one-third as much as Romney overall, with the other Republican candidates spending even less than McCain.
In the Republican ads, the main issues addressed were taxes, defense, abortion and immigration, according to the report. For Democrats, the main issue was health care, followed by economic issues.
Obama and Romney used the word ""change"" in one-third of their ads, while Clinton used it in only one-fourth. Clinton used the word ""experience"" more than the word ""change.""
Over 90 percent of ads were positive, with candidates talking about themselves, the report said.
Ken Goldstein is the director of the University of Wisconsin Advertising Project and a political science professor at UW-Madison. He said states with primaries following ""Super Tuesday"" are unlikely to see the levels of spending that appeared in the first contests.
""It is extremely unlikely that spending in all 23 Feb. 5 states - including the two largest states in the country - will reach the levels seen in Iowa and New Hampshire,"" Goldstein said in a statement.
Iowa and New Hampshire accounted for most of the ads aired. South Carolina, Nevada, Florida and Michigan saw considerably less advertising, according to the report.
Up to Jan. 27, only $8 million was spent in ""Super Tuesday"" states, with $3 million spent in California. On the Democratic side, Obama and Clinton accounted for all spending.
""Until this week, no Republican was on TV in these key states at all,"" Goldstein said.
More money was spent on advertising in Manchester, N.H., than in all the ""Super Tuesday"" states combined.
Nine days before the New Hampshire primary, $26 million had been spent on advertising there. At that point before the Iowa caucuses, $36 million had been spent.
