Today, after seven eventful years, attitudes toward President Obama will shape the selection of his successor.

The Republican base is infuriated by Mr. Obama’s activist view of government and progressive initiatives, from health care reform to immigration, gay rights to climate change.

Beyond specific issues, however, many Republicans view dimly the very qualities that played so well for Mr. Obama in 2008. Deliberation is seen as hesitancy; patience as weakness. His call for tolerance and passionate embrace of America’s growing diversity inflame many in the Republican base, who view with suspicion and anger the rapidly changing demographics of America. The president’s emphasis on diplomacy is viewed as appeasement.

So who among the Republicans is more the antithesis of Mr. Obama than the trash-talking, authoritarian, give-no-quarter Mr. Trump?