Barack Obama is running a half-hour prime-time commercial on NBC, CBS, Fox, MSBNC, and Univision Wednesday night, said James Hibberd in The Live Feed, but will anybody watch? Political ads, especially in swing states, are usually a “nuisance best avoided rather than Must See TV,” but viewers have tuned into the debates and conventions in record numbers this year, so maybe they'll watch this, too.

Nielsen ratings will be one measure of success, said Ira Teinowitz in TVWeek, but the ad also needs to convert undecided voters, motivate Obama backers, and drive TV and water cooler talk Thursday. Will it? Hard to say. No candidate has done this since Ross Perot in 1992, before the age of cable. Call it “Obama’s $3.5 million gamble.”

It’s one he can afford, said the Los Angeles Times in an editorial. Politicians don’t run national network ads anymore because there’s no need to sway voters in safe states like California or Texas. But Obama has the cash, and this kind of exposure might “run up his popular vote count nationwide.” That may seem unfair to John McCain, but “nobody ever said politicians were good sports.”