What Happened in Patrick Hope's HoD District Between the 5/1 BV Poll and the Primary?

Having looked at Alexandria and specifically at Adam Ebbin's State Senate district the other day, I wanted to finish revisiting our May 1 Blue Virginia poll results, focusing this time on Patrick Hope's 47th House of Delegates district. As you can see, the Blue Virginia poll had Hope leading by a 2:1 margin over Don Beyer in Hope's 47th House of Delegates district. Around 28% of voters in the district remained undecided as of May 1, with about 8% of the vote scattered among Adam Ebbin (3.2%), Lavern Chatman (1.8%), two candidates (Bruce Shuttleworth and Charniele Herring) who ended up dropping out (2.2% combined), and Mark Levine at 0.9%. What happened between May 1 and the election on June 10?See the graph below for the final 8th CD primary election results in the 47th House of Delegates district. What ended up happening was that Del. Hope basically kept his share in his own district, going from 44% in the May 1 BV poll to 45% in the final results (definitely within any conceivable "margin of error" on that one!). Meanwhile, Don Beyer picked up 14 percentage points, going from 21% on May to 35% in the actual election. To me, that's fascinating and a bit surprising, as I would have expected the undecided voters to break more towards a "new" candidate, perhaps Mark Levine (or Bruce Shuttleworth when he was in the race). Instead, it may have turned out that voters decided to go back to the candidate they perhaps saw as the "safe" choice, or who they remembered from when he was Lt. Governor, or from the Dean campaign or Obama administration or whatever. Also, I talked to Hope campaign manager Ben Tribbett, and he pointed to the Washington Post's May 24 endorsement of Beyer as accounting for most, if not all, of Beyer's gain in Hope's district. Basically, in Tribbett's view, a lot of voters in Hope's district liked both Hope AND Beyer, were trying to decide between those two candidates, and the Post endorsement was the tie-breaker in favor of Beyer (if it had been the other way around, Hope probably would have won his district by a significantly wider margin than he did, in Tribbett's view). Seems like a reasonable explanation to me, albeit kind of a pathetic one, given my almost complete lack of respect for the Post's editorial board or its Virginia endorsement "process" (in quotes because it's a complete joke; it's also really just one guy, Lee Hockstader, who never even comes to Virginia to cover any events). What about the other candidates, besides Hope and Beyer? They went from a combined 8% of the vote in the 47th House of Delegates district on May 1 to 20% of the vote in the actual election, an increase of 12 points combined. Most of those votes went to Ebbin (9%) and Levine (6%), who received a combined 15% of the vote in Hope's House district. Ebbin gained about 6 points from the May 1 Blue Virginia poll, while Levine increase by about 5 points. Of course, the 28% undecided made up their minds who to vote for, or decided not to vote. It appears that Beyer picked up almost all his extra 14 points out of those 28 points. The remaining 13.5 percentage points of the undecideds, plus the 2.2% for the two candidates who ended up dropping out, were mostly distributed to Ebbin and Levine. P.S. Ben Tribbett also pointed out that Hope performed the worst in precincts where he had never really run a competitive race, following 2011 redistricting. For instance, Beyer won the Park Lane district by a 106-58 margin over Hope.