Some Dems may have turned out, but at best it padded the win. Democrat turnout is expected to be low this year, as last mid-term...if they can’t get motivated to turn out in November, it’s highly unlikely a huge number came out for a June primary in the opposing party.
There were only 65,000 total voters or so... With democrats actively telling the loyal to show up and vote against Cantor its not hard to see 6,500 or more showing up to do so...
It will be interesting to see, but honestly the open primary thing is CRAZY.. never understood it.