Xingkerui,
If I'm reading what you wrote correctly I think you're saying that Dems should first get a lockdown on Obama-Trump voters before they target Romney-Clinton voters correct? If so, then I fully agree as somebody who knows the latter cohort quite well. I asked a DCCC consultant at my local campaign volunteer event about GOP rep-Clinton voters in and around Orange County and she told me clearly that those kind of voters were primarily republicans who didn't like Trump but were satisfied with their incumbent GOP reps based on the internal polling that had been done on them. Dissapointing albeit totally non-surprising answer.
I think Royce is the only vulnerable Republican in Orange County. Walters is probably fine and I think Rohrabacher is pretty safe. Issa is done but that's mostly due to San Diego County. And the reason why Royce is vulnerable and the others are not is because it has a lot of middle class areas with lots of minorities like Buena Park, La Habra and Fullerton in it. It also has places like Diamond Bar and Walnut, which are pretty wealthy, but have lots of minorities. They are more likely to swing at the congressional level than say Mission Viejo or Huntington Beach. The only city Walters needs to worry about is Irvine and Tustin, but other than that the district is full of wealthy white suburbanites. Villa Park is even in that district.....Rohrabacher has Newport Beach....Royce only has Yorba Linda and Brea to fall back on.
