The defection of Washington, D.C., lobbyist L. Charles Landgraf for Arnold & Porter means that there are no partners remaining in Dewey's office of the chairman, a five-lawyer group assembled in March to govern the firm in the face of mounting problems, Reuters reported yesterday. Stephen Horvath III, Dewey's executive partner in charge of day-to-day operations, appears to now be the top manager of what remains of the law firm. Of the roughly 300 partners with the firm in January, only around 50 remain. Dewey, which has about $225 million in debt, is facing a growing number of lawsuits dealing with everything from unpaid rent to pension funding. Instead of filing for bankruptcy, Dewey appears to be attempting to liquidate outside of court.