The June runoff will not be a two-way race. There will four names on the ballot: Busby, Bilbray or Roach, a Libertarian, and an independent candidate. So it will be possible for the winner (hopefully Busby, knock on wood) to win with less than 50%. The goal now is to come in first, regardless of whether she gets to 50%, the optimal situation. Those two additional names will attract votes.
I want to see a breakdown of the votes by precincts, but yesterday's returns were consistently between 42% and 44% throughout the night, including the absentee returns. That suggests to me that her support is consistent throughout the district. With that kind of a base and the upcoming general primary occurring at the same time as the runoff, I think she can improve on her vote enough so that she can win. But I also suspect that her win will be a squeaker.