When two Democrats are top two for lower offices we've seen one of them try to get Republicans to the polls. Usually these efforts are clumsy, as the Democrats doesn't know how to appeal to Republicans and fears turning off Democrats. Of course one of the candidates, likely Sanchez, will determine that Republicans favor her and higher Republican turnout will help her. From an election observer standpoint it'll be fascinating to see how the candidates will jockey for the 38-43% of the vote a Republican would get.
The San Jose Mercury News doesn't address whether it's good or bad for the GOP, but does highlight negatives for Democrats. The race would require massive spending by Democrats, money that could help them elsewhere. Kamala Harris won't be available to campaign for Hillary Clinton elsewhere.
Jerry Brown endorsed Harris today.
Jerry Brown officially endorsed Kamala Harris for Senate pic.twitter.com/Z8sfwyPX00— Phil Willon (@philwillon) May 23, 2016