WASHINGTON — Race, an inescapable but explosive issue on which both presidential candidates have tread carefully if not tried to ignore, is still popping up as it's becoming more likely the country will elect its first black president.

Some supporters of John McCain and Barack Obama, though not the candidates themselves, are amplifying the issue in the homestretch.

Among Democratic backers: Rep. John Lewis, a black Georgia Democrat and civil rights activist who accused the GOP ticket of "sowing the seeds of hatred and division" and recalled the atmosphere that segregationist Alabama governor George Wallace fostered in the 1960s; and Democratic Rep. John Murtha of Pennsylvania, who referred to the western part of his state as "a racist area."

Among GOP allies: a California group, which distributed anti-Obama literature with stereotypical black America images of a watermelon, ribs and a bucket of fried chicken. Another group put Obama's incendiary black former pastor, the Rev. Jeremiah Wright, in a TV ad. A Virginia GOP official jibed that Obama would hire rapper Ludacris to paint the White House black.

Among voters who haven't yet settled on a candidate: Joe the plumber. The Ohioan whose last name is Wurzelbacher and who was repeatedly mentioned during the final presidential debate told one interviewer he didn't get direct answers to his questions when he met Obama. He said all he got was "a tap dance. Almost as good as Sammy Davis Jr."

All that, and in the past week alone.

Polls show Obama, the Hawai'i-born son of a white mother from Kansas and a black father from Kenya, leading nationally and in key battlegrounds a little more than two weeks before the Nov. 4 election. He's already made history as the first black nominee of a major political party, and his candidacy has energized minority voters.

Among the unknowns: If Obama wins the White House, will racism become a subtext throughout his tenure? Or would his presidency soothe emotions still raw four decades after the civil rights movement and nearly 150 years since slavery ended?

Race has stayed in the background of the general election. Obama's campaign bristles at any suggestion of exploiting Obama's skin color; McCain's advisers deeply fear being called racists.

TAKING OFFENSE

But the issue boiled up a little over the summer. Obama said Republicans would try to scare voters by saying "he doesn't look like all those other presidents on the dollar bills." McCain's campaign, quick to counter any notion of racism, accused Obama of playing the race card.

A recent AP-Yahoo News poll found that 40 percent of white Americans hold at least a partly negative view of blacks. Such misgivings potentially could cost Obama the White House if the election is close.

In recently chastising McCain and running mate Sarah Palin, Lewis said, "There is no need for this hostility in our political discourse." He noted that Wallace while running for president "created the climate and the conditions that encouraged vicious attacks against innocent Americans who were simply trying to exercise their constitutional rights."

Later, Lewis said it was not his "intention or desire" to directly compare McCain or Palin to Wallace.

Obama's campaign said the Illinois senator didn't agree with any such comparison. But McCain challenged Obama personally at the debate to repudiate the remarks, which he called "very unfair and totally inappropriate."

Obama said Lewis' comments were not prompted by his campaign and that Lewis "inappropriately drew a comparison between what was happening there and what had happened during the civil rights movement."

LITTLE SKIRMISHES

• In San Bernardino County, Calif., the October newsletter of the Chaffey Community Republican Women, Federated, showed Obama's face on a phony $10 government food stamp coupon adorned with a watermelon, ribs and a bucket of fried chicken. Diane Fedele, president of the group, apologized and said she had no racist intent: "It was just food to me. It didn't mean anything else." The state GOP denounced the newsletter.

• In Nevada, Colorado and Michigan, TV ads show a clip of Wright declaring "God damn America!" in a sermon. "How can we forget these hateful sermons from Obama's pastor for over 20 years?" says one ad by the Our Country Deserves Better PAC, a Sacramento, Calif.-based group formed to campaign against Obama.

• In Pennsylvania, Murtha said, "There is no question that western Pennsylvania is a racist area," as he talked about Obama's prospects of winning the state. He later apologized and said, "While we cannot deny that race is a factor in this election, I believe we've been able to look beyond race these past few months."

• In Danville, Va., The Voice, a local newspaper, published a column by McCain's Buchanan County campaign chairman, Bobby May, that mocked an Obama administration. It said he would change the national anthem to the "Black National Anthem," mandate that churches teach black liberation theology, appoint Al Sharpton and Jesse Jackson to the Cabinet and put prominent blacks like Oprah Winfrey on currency. McCain's campaign dropped May from his job.

• In West Plains, Mo., a town of 10,000 people near the Arkansas border, a prominent highway sign by an unknown creator shows a turban-wearing cartoon caricature of Obama, with an exaggerated smile, full lips and oversized teeth. It says: "Barack 'Hussein' Obama equals more abortions, same-sex marriages, taxes, gun regulations."