It's interesting that Arkansas (primary this coming Tuesday, May 27), this year at least, has its (primary (the only runoff Arkansas has)) runoff (where necessary, and there are three Republicans running for the open AR-02 seat this year) only three weeks later, Tuesday, June 10. South Carolina has only a two weeks between it's primary on June 10 and it's (primary) runoff on Tuesday, June 24, and as both dates are in June I imagine that 14-day gap is the same regardless of which of how the days of the week and dates of the year add up.
Interestingly, and I looked into this because Maine's primary is on the 2nd Tuesday in June, for any
n, the
nth Tuesday in June will always fall the same number of weeks before the first Tuesday after the first Monday in November (Election Day). For the 2nd Tuesday it's 21 weeks (147 days). The same would apply (as far as days or weeks and days goes) for a primary or primary runoff the first any other day or the week after the
nth Tuesday in June (or the
nth other day or the week after the first Tuesday in June). To have that property, a day based off a day in another month would have to be based off a Friday in January, a Monday (like Election Day) in February or March, a Thursday in April, a Saturday in May (would work well for Louisiana, except for how early it is for a state where it's jungle primary can be the only election for a given office), a Thursday in July, a Sunday in August, a Wednesday in September, a Friday in October, a Monday in November (for some general election runoff from here on out), a Wednesday in December (Louisiana's runoff for congressional elections is on the first Saturday after the first Wednesday in December, always five weeks after Election Day when it's congressional jungle primaries are held), or a Saturday in the following January (Georgia's general election runoff is by law I guess 9 weeks after Election Day, but that will always be the first Tuesday after the first Saturday in January).
Georgia has that same 9-week gap between it's primary and primary runoff. It's primary is always 24 weeks before Election Day (the first/third Tuesday after the third/first Saturday in May, or simply the last Tuesday in May, it turns out (that's being based off the first Tuesday in June)), and it's general election is the 15 weeks before Election Day (the first/third Tuesday after the third/first Thursday in July). Texas has a 12-week gap, this year at least, although I'm not sure if that's a constant or not. North Carolina (this year at least) and South Dakota each have a 10-week gap, although the 35% a candidate needs to get to avoid a runoff in South Dakota is even lower than North Carolina's 40%. The wording
here suggests that South Dakota's runoff provisions only extend to primaries for Governor and both houses of Congress, and South Dakota doesn't seem to have the political culture (or the multiple congressional districts) that would lead to a primary winner's vote percentage for one of these races to fall below the 35% threshold often. Oklahoma has the same 9-week gap as Georgia (this year at least), although without Georgia's provision for a general election runoff. Alabama has a six-week gap (this year at least), while Mississippi has the same the same three-week gap as Arkansas, and as Mississippi has both its primary and (primary) runoff elections in June I imagine there's the same gap election year to election year.
