After months of arguing that the US can’t afford to shut down Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC), Rafferty Capital Markets VP of equity research Richard X. Bove is changing tack. This time he’s writing an open letter to President Obama that congratulates him on saving the GSEs and urges him to avoid the political and financial fallout from what could be their messy dissolution. “As a consequence of what you did the American people were still able to conduct transactions in the housing market during…