‘Pick the target, freeze it, personalize it, and polarize it,” wrote Saul Alinksy in his “Rules for Radicals.” The White House would appear to have a copy. His agenda stymied and his approval numbers sinking, President Obama has realized this year’s midterm election is shaping up as a referendum on failed Democratic governance. The new White House plan? Change the discussion, talk about Republicans, and frighten the nation about GOP ideas. This is the way to read Mr. Obama’s sudden re-embrace of his opposition-his unexpected appearance at the House Republican retreat, and his more recent invitation to Republicans to a “bipartisan” health-care summit. And it’s the way to understand the recent Democratic targeting, freezing, personalizing and polarizing of Rep. Paul Ryan.