A week ago, Republicans surged to what was described as an "unprecedented" 10-point advantage in Gallup's survey of congressional voting preference.
Now, the pollster finds Democrats and Republicans tied in its so-called generic ballot test, a swing that would seem just as remarkable.
Gallup surveyed 1,650 registered voters between Aug. 30 and Sept. 5, a period that included President Obama's nationally televised address on Iraq and a new jobs report showing only meager improvement in private-sector hiring.
Asked if they preferred a Republican or Democratic candidate in November, 5%1 chose the Republican and 41% the Democrat in Gallup's previous survey. Now, the parties are knotted at 46% apiece. It's the first time in more than a month that Democrats have not trailed.