Gallup polls for the last few days show Mrs. Clinton in about a 5% lead over Mr. Obama--her first statistically significant lead since early February. There are a few potential explanations for her new lead: momentum from her wins in Texas and Ohio, her expected win in Pennsylvania, and the backlash against Mr. Obama from the now infamous sermon from Reverend Jeremiah Wright, Jr.
The question, of course, is just how much of the increase is based on Rev. Wright's speech, and how will the fallout from that speech affect the polling numbers? When Mrs. Clinton initially moved ahead in the polls, the polling data was taken in the immediate aftermath of Wright's remarks. However, as we all know, Mr. Obama made what was widely regarded as a moving and poignant speech on race in America on Tuesday. Gallup reflects that Wednesday's numbers improved for Mr. Obama--indicating that perhaps his response stemmed the tide, so to speak. The telling information should come in polls the rest of this week and early next week to see how voters react to Mr. Obama's response.
For some information on how general election polling has shifted because of the "Wright-Controversy," see this article on Real Clear Politics. And lest we ignore the inevitable inter- and intra-party sniping that Rev. Wright hath wrought, here is a nice summary from Citizen Kendrick's old favorite, The New York Times.