Jan 22 09:17 AM US/Eastern WASHINGTON (AP) - Senate Republicans return to work Monday in an angry mood. They're upset about President Barack Obama's appointments to two key agencies during their break. Less clear is what they'll do in responding to Obama's decision to get around their blocking strategy by filling four top government positions. Obama used what are known as recess appointments to put Richard Cordray in charge of the new Consumer Financial Protection agency and put three new members on the National Labor Relations Board. Sen. Charles Grassley, the senior Republican on the Senate Judiciary Committee, predicts his party will take some action, but he isn't offering any details. Republicans say Obama's appointments were unconstitutional because the Senate technically remained in session even though it conducted no business. Obama and his Justice Department rejected that analysis.