Big money is being spent this week by the political parties and outside groups in the Indiana Senate contest between Democrat Joe Donnelly and Republican Richard Mourdock.The Democratic Senatorial Campaign Committee has reportedly bought another $439,000 in advertisements for this week and the National Republican Senatorial Committee is following suit. For the past week, the conservative super PAC American Crossroads bas been running a nearly $1 million ad buy against Donnelly for his votes in support of President Obama's agenda. But a gang of liberal organizations led by Senate Majority Leader Harry Reid's Majority PAC, announced Tuesday that they are launching a $1 million campaign against Mourdock this week to highlight his opposition to the auto bailout.Check it out:Majority PAC will be joined by AFSCME and Center Forward in the TV ads.