Short answers, pulled from the story.
McDonald held the most conservative voting record of any Democrat in Congress. The American Conservative Union gave him a perfect score of 100 every year he served, except in 1978 when he scored 95. A scoring method published in the American Journal of Political Science ranked him the second most conservative member of either chamber between 1937 and 2002, behind only Ron Paul.
McDonald was killed on the 1st of September, 1983, when Korean Air Lines Flight 007 was shot down after entering Soviet airspace. Soviet forces under the command of General Anatoly Kornukov intercepted the aircraft. None of the passengers or crew survived.
McDonald became chairman of the John Birch Society in 1983, succeeding Robert Welch. He had joined the organization in 1966 or 1967 and held the chairmanship for only a few months before his death that September.
McDonald co-founded the Western Goals Foundation in 1979 alongside John Rees and Major General John K. Singlaub. The Spokesman-Review described its mission as blunting "subversion, terrorism, and communism," filling the gap left by the disbanding of the House Un-American Activities Committee. At the time of McDonald's death, the organization was being sued by the ACLU for obtaining and computerizing illegal Los Angeles Police Department intelligence files.
Bad weather on the 28th of August, 1983 diverted McDonald's flight from Atlanta to Baltimore. He arrived at JFK Airport in New York and missed his connection to Seoul by two or three minutes. Rather than board an available Pan Am Boeing 747, he chose to wait two days for the next Korean Air Lines flight, preferring its lower fares.
A special election was held after McDonald's death to fill his seat representing Georgia's 7th congressional district. His widow, Kathy McDonald, ran for the seat but lost to George "Buddy" Darden.