The presidential candidates spent $28.3 million on TV advertising during the week of Sept. 28 to Oct. 4, and devoted most of it to negative ads, according to research from the University of Wisconsin Advertising Project.  The Project found that Sen. John McCain spent nearly $10.9 million on TV ads that week, with nearly all of them considered negative, and Sen. Barack Obama spent $17.5 million, with 34 percent considered negative. Spending totals on negative ads is difficult to break out as the campaigns buy ad time in different markets with different costs.  Obama referred during the presidential debate on Wednesday, Oct. 15 to McCain’s reliance on negative ads though the Illinois Senator didn’t mention the Advertising Project as the source.  The two candidates spent $14.6 million, or a little more than half their TV ad budgets, in seven Midwestern states where the two campaigns have been running very close. McCain devoted 60 percent of his spending and Obama nearly 47 of spending to running ads in Indiana, Iowa, Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin.  So far, the amount of negative advertising is up in this election cycle compared with that of 2004. Through that entire cycle, 64 percent of Pres. Bush’s ads and 34 percent of those of Sen. John Kerry were negative. In comparison, 73 percent of McCain’s TV ads through Oct. 4 were negative, while 61 percent of Obama’s were negative, the Project found. The Wisconsin Advertising Project codes political television advertising for sponsors, issues, tone and other characteristics. It is funded by the Joyce Foundation.