Wait ... Louisiana Governor used to be an on-year election?
No, this election actually took place across three rounds which extended into the following year. First, the primaries took place on general election day 1971 (i.e. November 6th). Then there was a runoff for the Dem primary on December 18th. Then finally the general election took place on February 1st 1972.
http://en.wikipedia.org/wiki/Louisiana_gubernatorial_election,_1971%E2%80%9372
So when did they start doing the jungle primary?
After the 1971-2 election. Edwards received about 1/4 of the vote in the Democratic 1st Primary, in which over a million votes were cast. Meanwhile Treen was nominated in the Republican 1st Primary in which under 10,000 votes were cast.
Edwards was narrowly nominated in the 2nd Primary, and then had to defeat Treen in the general election. Fewer votes were cast in the general election than the 2nd Primary, but it appears that all of Johnston's support went to Treen.
Previously, the general election had been a superfluity; so it was logical for it to be eliminated. It was also hoped that it would eliminate a Republican getting traction from a one-on-one election. The constitution does not specify the manner of election.
Edwards took office in May 1972, so that a January election was not that odd. The 1974 constitution moved the beginning of the term to March, and with an amendment adopted in 1986, effective in January 1992, moved the beginning of terms to January. The legislature continues to meet in March of even-numbered years.
The primary in 1971 was, like most (all?) non-federal elections in Louisiana, was on a Saturday. The current election date for the Open Primary and the runoff are in mid-October and mid-November of an odd-numbered year (legislators and executive offices, both serve 4-year terms).
