Talk about coattails!  Gallup’s latest polling now shows Republicans within the margin of error on the generic Congressional ballot nationwide, up from a double-digit deficit just two weeks ago.  The selection of Sarah Palin has energized the Republican base, motivating them to vote even more than Democrats:

A potential shift in fortunes for the Republicans in Congress is seen in the latest USA Today/Gallup survey, with the Democrats now leading the Republicans by just 3 percentage points, 48% to 45%, in voters’ “generic ballot” preferences for Congress. This is down from consistent double-digit Democratic leads seen on this measure over the past year. …

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.

The erosion began last month, and may result from a double whammy of sorts.  The Palin effect may have energized the base, but the gain among independents may be more likely the result of the Democratic punt on energy in August.  Nancy Pelosi shut down Congress rather than allow a vote on expanded drilling, a huge miscalculation with an electorate favoring that policy by more than 2-1.

This also indicates that Democratic efforts to run against George Bush again have failed.  Gallup suggests that the Republican brand has begun an abrupt recovery with the transfer of symbolic leadership to two proven reformers, McCain and Palin.  From this point forward, Bush is irrelevant to the election, and Team Obama’s constant “four more years” refrain hasn’t any resonance except among the already-committed Democrats.

If Democrats lose the House, they can look back to Pelosi’s adjournment as their tipping point.  She may have singlehandedly transformed her party, which looked like it couldn’t lose this year, into a minority in the House.