The pilot stated that he flew a stabilized approach and had a normal touchdown. After touchdown the airplane veered to the left, and he compensated with right rudder but got no response. As the airplane drifted to the left, he increased the right rudder inputs and also used right toe-brake but again got no response. Before exiting the runway he pulled the handbrake while applying hard right toe-brake. The aircraft did slow but didn't turn to the right. After exiting the runway the airplane overran the VASI light system and struck a row of runway lights. After which the airplane impacted an embankment and slid obliquely down the side of it. The airplane then impacted another embankment perpendicular to that one, shearing the nose-wheel, bending the prop and engine-cowl. The airplane then rolled to the left and the wing struck the ground, buckling the inboard side fuel tank bulkhead and partially shearing from the fuselage before it come to a stop. The pilot stated that the airplane's nosewheel steering and brakes performed normally prior to the accident flight. The responding FAA inspector stated that examination of the site indicated that the airplane touchdown point was 25 yards from the end of the runway and 8 yards left of the centerline, and angled directly towards the second VASI light installation. Following the tire tracks it appears that the underside of the left wing impacted the VASI light. The pilot stated to the FAA inspector that there were no mechanical difficulties with the aircraft.