Hillary Clinton and Barack Obama are suffering in the polls from their prolonged and increasingly bitter primary fight, a new Wall Street Journal-NBC News survey suggests.

The poll, released Wednesday, showed Obama's speech on race and the attention paid to comments by his longtime pastor, the Rev. Jeremiah Wright, so far have had little effect on the Democratic race. The survey showed the Democratic candidates are still in a dead heat, each with 45 percent support among Democrats.

But the candidates have individually lost ground with voters -- more voters see the Democrats in a negative light than they did just two weeks ago in a similar poll. This is especially true for Clinton.

The poll, taken from March 24-25 of 700 registered voters, showed 48 percent of voters view Clinton negatively, compared with the 37 percent who view her positively. Just two weeks ago, 43 percent viewed her negatively and 45 percent viewed her positively.

For Obama, 32 percent view him negatively and 49 percent view him positively. That's a slight change from two weeks ago, when 28 percent viewed him negatively and 51 percent viewed him positively.

This could bode well for presumptive GOP nominee John McCain, whose numbers have stayed strong as Obama and Clinton bicker. McCain was still viewed positively by 45 percent of those surveyed, compared with just 25 percent who viewed him negatively.

Obama has had to respond in recent weeks to videos of Wright's sermons, including one in which he shouts "God damn America" for its treatment of minorities. Wright also has said the U.S. government invented AIDS to destroy "people of color" and has suggested U.S. policies were to blame for the 9/11 attacks.

In a speech last week, Obama rejected Wright's divisive comments but stood by him otherwise and said it is time for the country to address its racial schism.

By 55 percent to 32 percent, more who had seen or heard about Obama's speech said they were satisfied with his explanation of his association with Wright than said they were dissatisfied.

Yet people familiar with Obama's remarks were about evenly split between those who said they felt reassured about his feelings on race, and those who said they still had doubts. Slightly more said Obama has said enough about race than said he needs to address it further.

In all instances, whites were more dubious than blacks about whether Obama had handled the issue successfully. Democrats were far more supportive than Republicans, while independents were likelier to be divided.

Meanwhile, Clinton has helped keep the issue on the radar screen, saying for the first time this week that Wright would not have been her pastor.

Click here to see the Wall Street Journal-NBC News poll.

The Associated Press contributed to this report.