In 2012, the Florida Commission on Ethics cleared Rubio of wrongdoing in his use of the party-issued credit card, although the commission inspector said that Rubio exhibited a "level of negligence" in not using his personal MasterCard. In November 2015, Rubio released his party credit card statements for January 2005 through October 2006, which showed eight personal charges totaling $7,243.74, all of which he had personally reimbursed, in most instances by the next billing period. When releasing the charge records, Rubio spokesman Todd Harris said, "These statements are more than 10 years old. And the only people who ask about them today are the liberal media and our political opponents. We are releasing them now because Marco has nothing to hide." Professorship After leaving the Florida Legislature in 2008, Rubio began teaching under a fellowship appointment at Florida International University (FIU) as an adjunct professor. In 2011, after entering the U.S. Senate, he rejoined the FIU faculty. Rubio teaches in the Department of Politics and International Relations, which is part of FIU's Steven J. Green School of International and Public Affairs. He has taught undergraduate courses on Florida politics, political parties, and legislative politics. Rubio's appointment as an FIU professor was initially criticized. The university obtained considerable state funding when Rubio was speaker of the Florida House, and many other university jobs were being eliminated due to funding issues at the time FIU appointed him to the faculty. When Rubio accepted the fellowship appointment as an adjunct professor at FIU, he agreed to raise most of the funding for his position from private sources. U.S. Senate Elections 2010 On May 5, 2009, Rubio stated his intent to run for the U.S. Senate seat being vacated by Mel Martínez, who had decided not to seek reelection and subsequently resigned before completing his term. Before launching his campaign, Rubio met with fundraisers and supporters throughout the state. Initially trailing by double digits in the primary against the incumbent governor of his own party, Charlie Crist, Rubio eventually surpassed Crist in polling for the Republican nomination. In his campaign, Rubio received the support of members of the Tea Party, many of whom were dissatisfied with Crist's policies as governor. On April 28, 2010, Crist said he would run without a party affiliation, effectively ceding the Republican nomination to Rubio. Several of Crist's top fundraisers, as well as Republican leadership, refused to support Crist