U.S. Rep. Dave Loebsack joined the Center for Plain Language on Tuesday in issuing its annual Federal Plain Language Report Card that shows federal agencies have made progress in how clearly they communicate with the nation’s taxpayers, but have room for improvement.The Social Security Administration and Department of Homeland Security tied for top grades and the Departments of State and Transportation received the lowest grades, according to the Iowa City Democrat, who has taken up the challenge of former 1st District U.S.