Is there evidence of a Democratic Party surge?

This doesn't quite fit in with the Republican Party's narrative about the November midterm elections. The Democrats have regained the lead in the congressional ballot poll according to an Associated Press/GFK poll released today. This coincides with a surging approval rating for President Obama in numerous polls, including the Gallup Tracking Poll. Does this mean the Democrats are headed for less significant losses in November, and if they are, what is driving this reversal of fortune?

As Bill Clinton would say, it's all about the economy stupid. After recent economic reports, it's looking like the economy will be adding more jobs in the first two years of the Obama Administration than were created during the entirety of the Bush years. This should be sending shivers down Republicans' spines as they have been campaigning against the Administration's economic policies for much of the election season. This narrative will be difficult to hold once the economy is in a distinctive upswing, which looks more and more likely now.

One other conclusion is that the oil spill has solidified the public's opinion against the corporatism the Republicans in congress espouse. Rush Limbaugh telling his viewers the oil spill is not a problem may be acceptable for uber-conservative primary voters, but the average American really likes beaches in Florida (and maybe are worried about some dead sea gulls). The financial reform bill before congress could have this same effect. Republicans will have a hard time facing the voters if they outright oppose financial reform. The polls do not show a successful Democratic year, but may help to alleviate fears of a 1994- like disaster for the incumbent party.