As I was looking over a different graphic last week about Virginia having no Republican Primary on Super Tuesday, I started thinking about whether or not the people in the Elephant Clan would actually do what they so vehemently complain about … cross over on Super Tuesday.
Lo and behold, I stumbled across a graphic on VPAP  that examined crossover voting in 10 Primary Contests. I noticed a couple of things that I believe are important. First and most obvious, BOTH parties will vote in the opposition’s primary, and more often than not it does not matter.
The VPAP graphic lists the 10 primary contests they compared by the party and percentage of crossover. If you break these races down, in four out of 10 contests (2018 USHD4, 2015 VA.HD 2, 2015 VA.HD 16, 2015 VA.SD  28), the crossover made no difference whatsoever.
In the contests that the crossover might have mattered, there was either no General Election challenger (2015 VA.HD 29 and VA.HD 79), or the Primary was a three-way contest ( 2016 USHD 2, 2015 VA.SD  10 2015 VA.SD  11, and VA. SD 24).
Here are the contests where the crossover voters had no effect on the outcome:
US House District 4: 2018 Republican Primary 11.9% Democratic Crossover
Fenty: 27.43% The crossover had no effect on the outcome
VA HOD District 16: 2015 Democratic Primary 5.9% Republican Crossover
Preston 37.95% The crossover had no effect on the outcome
VA HOD District 2: 2015 Republican Primary 7.4% Democratic Crossover
Ciampaglio 40.51% The crossover had no effect on the outcome
VA HOD District 28 2015 Republican Primary 6.0% Democratic Crossover
Stimpson 37.91% The crossover had no effect on the outcome
Here are two examples of where the crossover might have mattered:
VA HOD 79: 2015 Democratic Primary 15.6% Republican Crossover
Jounnou 47.23% The crossover might have mattered; no General election challenger
VA HOD 29: 2015 Republican Primary 9.9 % Democratic Crossover
Berg: 48.09% The crossover might have mattered; no General election challenger
I didn’t include the three-way contests because even though some of them were suggestive, there is no way to know if the crossovers mattered more than the presence of a third candidate.
Some of the crossovers were obviously … strategic, which lends to the argument of running opponents in as many races as possible. If both parties had primaries on the same day, it might finally settle the age-old convention v. primary argument.
What I did not see within the numbers was a definitive, “The other party is choosing our candidate,” argument. That was also interesting.