Mitt Romney has so far released only one year of tax returns (2010), plus an estimate for 2011. This stands in stark contrast to his father, Michigan Governor George Romney, who released 12 years of tax returns when he began running for President in 1967. As his father said at the time, "One year could be a fluke." So the questions remain about what is in Romney's older returns. Two stories this week and last have ratcheted up the pressure. One is a recent web exclusive for "The Last Word with Laurence O'Donnell" where David Cay Johnston has five...