Flandreau, S.D. ? Rep. Bill Janklow, the hard-charging former governor who has been a dominating force in South Dakota politics for 30 years, was charged with second-degree manslaughter Friday for allegedly barreling through a stop sign at more than 70 mph and colliding with a motorcyclist.

Bill Ellingson, the prosecutor in Janklow’s home county, also charged the congressman with failure to stop, speeding and misdemeanor reckless driving for the Aug. 16 crash that killed Randy Scott, a 55-year-old farmer from Hardwick, Minn. Janklow hurt his head and right hand in the crash.

The manslaughter charge carries up to 10 years in prison and a $10,000 fine if convicted.

The charge throws the future of South Dakota’s lone House member into doubt and tarnishes a storied political career that includes four terms as governor and one as state attorney general. The 63-year-old Republican has an initial court appearance Tuesday — the same day Congress reconvenes after its August break.

Investigators say Janklow was doing 71 mph in his Cadillac when he ran the stop sign Aug. 16 near Trent, a small town near the Minnesota line. Janklow, who has a history of driving fast, told an investigator he saw the sign but was going too fast to stop before colliding with the bike.

Ellingson refused to talk with reporters, but said in a news release that manslaughter charges in traffic accidents were warranted in cases where there was “a conscious and unjustifiable disregard of a substantial risk.”

Janklow would not comment. But his son, attorney Russell Janklow, said it would be inappropriate to talk about the case.

“Any discussions that should and would be done will be done at the courthouse and that’s the appropriate place for it,” he said.

Some political watchers believe the same rural intersection that took Scott’s life also claimed Janklow’s political career.

“I think he was politically vulnerable before the accident. Since the accident, I think his political future has been sealed,” said Jim Meader, an Augustana College government professor and polling expert.

If a congressman is convicted of a felony, the U.S. House of Representatives ethics committee would automatically investigate.

The committee’s rules say representatives who plead guilty or are convicted of a crime that carries more than two years in prison cannot vote in the chamber until his or her record is cleared, or until re-elected.