WASHINGTON (CNN) -- After tapes of inflammatory statements made by Sen. Barack Obama's pastor came out last weekend, it appears to have had some negative impact on the Illinois senator.
Sen. Barack Obama and his church's former pastor, the Rev. Jeremiah Wright, in a 2005 photograph.
Nationally, Obama's lead over Sen. Hillary Clinton narrowed in a poll of polls -- which included CBS News, USA Today and Gallup.
The polls, taken between March 14-18, show Obama with 49 percent to Clinton's 43 percent.
"I don't think there is any doubt that the [Rev.] Jeremiah Wright controversy played a role in the 10-point drop in his favorable ratings," said pollster Terry Madonna. Watch reaction to Wright's comments »
Some of Wright's old sermons came under fire after a news report last week turned some of his most controversial comments into a YouTube phenomenon.
In one, the minister said America had brought the September 11 attacks upon itself. In another, he said Clinton had an advantage over Obama because she is white.
Speaking in Pennsylvania at Philadelphia's National Constitution Center Wednesday, Obama, a Democratic presidential candidate, said he rejected racially charged comments. Watch Obama discuss the Wright controversy with CNN's Anderson Cooper »
"Did I strongly disagree with many of his political views? Absolutely -- just as I'm sure many of you have heard remarks from your pastors, priests or rabbis with which you strongly disagreed."
The controversy appears to be having a big effect in Pennsylvania.
Among Pennsylvania Democratic primary voters, Clinton's lead over Obama more than doubled from last month, according to polls.
Obama's association with Wright appeared to be hurting him as of last weekend.
A Franklin & Marshall College Poll taken February 13-18 showed Clinton with 44 percent, Obama with 37 percent. When voters were asked March 11-16, Clinton had 51 percent to Obama's 36 percent.
A Gallup tracking poll, taken from March 15-21, showed Obama's race speech may have helped him.
Clinton started moving ahead of Obama last weekend when the Wright story broke. By Tuesday, she had a statistically significant 7-point lead.
Then Obama spoke about his relationship with Wright and his view of race relations. Clinton's lead began to narrow, to 5 points and, as of Friday, 2 points.
Friday's results -- statistically, a tie -- represent the first poll in which all interviews were done after Obama's speech. E-mail to a friend