Consider definitely non-purple states with open primaries. We can often get the situation we have now in California where voters in the minority party know that their vote for the president will almost certainly have no impact on the outcome and they have no option to vote for a member of their own party in one or more major state-wide race. What impact might this have on minority party districts in the state?
While it is still too early to say what that impact might be, it is fair to say that it does have some people worried.
Matthew Artz writing for the Mercury News [emphasis added]:
While Democrats have little chance of winning the 30 seats needed to retake the House, they could make a bigger dent than expected in California with four Republican incumbents now facing competitive races: Jeff Denham and David Valadao in the Central Valley, Steve Knight in Los Angeles County, and Darrell Issa in the San Diego suburbs.
The nonpartisan Cook Political Report recently declared three of those races “tossups” while downgrading Valadao’s seat from “likely Republican” to “lean Republican.”
Local GOP candidates were never going to get much help from a ballot in which two Democrats are competing for the open U.S. Senate seat, and no ballot measure has captured the imagination of Republican voters. But Trump’s dismal poll numbers makes their plight even more difficult, said Bill Whalen, a former Republican operative who is now a research fellow at Stanford’s Hoover Institution.
“Twenty-eight percent is uncharted territory,” he said, noting that the worst showing by a Republican presidential nominee in California was Alfred Landon, who won 31 percent of the vote in 1936. John McCain and Mitt Romney each won 37 percent.
“Republicans should be concerned,” Whalen said. “The numbers are dreadful.”