About 6 percent of voters in Virginia's Republican primary were Democrats, according to a CNN exit poll.
That jibes with anecdotal evidence of Democrats voting in the opposite party's primary strategically — though whether "strategically" translated into "for Donald Trump" (because they thought Trump would be easy to beat) or "against Donald Trump" (because they were horrified by the prospect of a Trump presidency) isn't yet clear.
But this number should be taken with two big grains of salt. First, it's a small sample size from an early exit poll in a state that's still too close to call.
Second, Democrats crossing the aisle in Virginia is a time-honored tradition. In 2012, 5 percent of Virginia's Republican primary voters were Democrats, according to CNN. In 2008, 3 percent were — during a bitterly fought Democratic primary when Democrats had good reason to weigh in on their own party.