Former House Speaker Newt Gingrich has quietly positioned himself for a comeback to head the Republican Party as early as 2008. GOP sources said Mr. Gingrich does not plan to run for president, but intends to be available as the savior of conservatives dismayed by candidates who seek to move the party to the left in the aftermath of George W. Bush’s presidency. Over the last few months, Mr. Gingrich has become the favorite of conservatives and has outlined a new vision for the GOP that seeks for the party to return to the moral clarity of the late President...