Could we be headed for a Thomas Dewey - Harry Truman kind of election? A day - let alone a week - is a long time in politics so anything can happen but today's news from Gallup has got to be sending shockwaves through the Democratic party: "The positive impact of the GOP convention on polling indicators of Republican strength is further seen in the operation of Gallup's "likely voter" model in this survey. Republicans, who are now much more enthused about the 2008 election than they were prior to the convention, show heightened interest in voting, and thus outscore Democrats in apparent likelihood to vote in November. As a result, Republican candidates now lead Democratic candidates among likely voters by 5 percentage points, 50% to 45%. If these numbers are sustained through Election Day -- a big if -- Republicans could be expected to regain control of the U.S. House of Representatives. As Gallup's long-term "generic ballot" trend shows, the Democrats held a sizable lead on this measure from the time they won back control of Congress in the fall of 2006 through last month. If the current closer positioning of the parties holds, the structure of congressional preferences will be similar to most of the period from 1994 through 2005, when Republicans won and maintained control of Congress.