"Look: Republicans can decide for themselves if they want to go to war. If they want to pass yet another bill repealing Obamacare, that's fine. If they want to sue the president over the EPA or immigration, that's fine. If they want to approve the Keystone XL pipeline, that's fine. I assume Obama will win some of these battles and lose others, but in any case will treat them as the ordinary cut and thrust of politics instead of declaring them calculated insults that have infuriated him so much he can't possibly ever engage with the GOP again. In other words, he'll act like an adult, not a five-year-old."