First there were four, then a fifth, and now one more member of Congress found to be illegally exploiting a tax break for District residents who are homeowners. Via Politico, the Kansas City Star is reporting that Rep. Roy Blunt (R-Mo.) and his wife have been caught claiming the homestead exemption on their $1.6 million Georgetown home. The exemption offers District residents a deduction on the assessed value of their D.C. home and limits…