Argument: Open primaries preserve right of parties to endorse nominees
Susan Nielsen. "Open Oregon's primaries." Oregonian. October 13, 2008: Open primaries "would preserve parties' constitutional right to designate their own nominees. Ballots would list each candidate's party affiliation, as well as any official party endorsements. Parties would retain quite a bit of flexibility: For example, they could endorse multiple candidates (or none) in a primary race, then pick one (or both) in the general."
George Skelton. "California open primaries. Give them a chance." Los Angeles Times. February 11th, 2010: "Party officials despise any form of open primary because they fear losing power, as if they've ever had much in California anyway. But party conventions still could endorse candidates."