Republican Sen. Charles Grassley has blocked the ambassadorial nomination of Alan Solomont, currently chairman of the board of the government agency that oversees AmeriCorps, in retaliation for what Grassley says is the administration's stonewalling of Congress over documents relating to the firing of AmeriCorps inspector general Gerald Walpin. Specifically, Grassley has sought, and been denied, information relating to the White House's role in the decision to fire Walpin. Solomont, a major Democratic donor, is chairman of the Corporation for National and Community Service, which includes AmeriCorps. His term ends in October, and President Obama has nominated him to be U.S....