(CNN) -- Are white Americans turning against Barack Obama because of the color of his skin?
Former U.S. President Jimmy Carter told NBC that racism has surfaced in opposition to Barack Obama.
After weeks of growing opposition and the largest protest of his eight-month presidency, some of his supporters think so.
"An overwhelming portion of the intensely demonstrated animosity toward President Barack Obama is based on the fact that he is a black man," former president Jimmy Carter said this week.
Many Americans have been shocked by protestors' posters depicting the president in the crudely stereotyped garb of an imaginary African witch doctor. Do you think attacks on Obama have been motivated by race?
When a lawmaker from South Carolina screamed out "you lie" as Obama delivered a nationally-televised address, former president Carter, among others, suggested the South's history of racism contributed to the congressman's contempt.
Popular right-wing broadcaster Glenn Beck even accused the president of secretly using his entire legislative agenda to avenge African-American suffering.
Beck said it's "all driven by President Obama's thinking on one idea: Reparations."
The most common and colorful anti-Obama demonstrations have been dubbed "tea parties." They've been boisterous right-wing rallies named after a colonial-era uprising known as the Boston Tea Party.
The new tea parties have had no obvious link to race, except for a handful of protestors with the witch-doctor signs. Other signs insulted white politicians too.
In Washington last weekend, when at least 50,000 people gathered for the largest protest, the crowd was almost all white, but that's hardly a surprise; African-Americans are generally supportive of the African-American president.
Lloyd Marcus, an African-American activist and entertainer who boasts that he's taken part in 34 tea party rallies, blogged that he felt welcome at them all.
"The racial hate expressed against me came from the left, people who support President Obama's radical socialist agenda."
Obama himself says there has been "a coarsening of our political dialog," but he hasn't said race is the reason.
Americans are prone to the same prejudices known everywhere, but they are also passionate about politics.
President Obama is fighting two wars, an economic downturn and a battle to reform the U.S. healthcare system. He's running into a lot of opposition purely because of his policies.
Americans aren't colorblind and some assuredly remain racist. But that probably isn't the president's biggest problem.