A new poll from the Wall Street Journal says if Nikki Haley wins the Republican nomination, she would beat President Biden by 14 points. Donald Trump is four ahead, and Ron DeSantis ties Mr. Biden. The poll is simply a snapshot but demonstrates a few important things. Because Ambassador Haley is not controversial, she polls well among non-political Americans who reject Mr. Trump's demeanor and don't really care how he governs. But committed Republicans continue to overwhelmingly back the former president because they perceive Ms. Haley as an establishment politician who will not aggressively challenge the ingrained liberal system in...