David Axelrod, the political strategist who helped Barack Obama secure two terms in the White House, has warned that racial "fear" and hostility towards the first black US president has infected American politics and is partly to blame for Republican intransigence in confronting the president's agenda. In an interview before the release of his new autobiography, Axelrod spoke in frank terms about what he perceives as the corrosive influence of race in the Obama era. The former White House adviser said "no other president" in US history had had a member of Congress shout at him in the middle of a major address - as Joe Wilson of South Carolina did in 2009 with his notorious "You lie!" rebuke - or face "persistent questions" about his American citizenship, as Obama did from the "birther" movement. "The fact is, there are some people who are uncomfortable with the changing demographics of our country," Axelrod said. "To those people, Obama is a living symbol of something they fear, they don't like, and some of that has spilled into our politics." During the course of back-to-back presidential campaigns as Obama's top strategist in 2008 and 2012, as well as during two years in the White House before turning to consulting and TV commentary, Axelrod generally kept his thoughts about race to himself. He didn't want to imply that all political opposition to Obama in Washington was race-based or that the president saw himself as a victim. "I never talked about it because I never wanted to imply we were ascribing all opposition to race because much of it was just philosophical differences," Axelrod said. But more than two years removed from daily presidential politics, Axelrod is speaking out. "There was no doubt that there was a core of the hostility motivated by race," he said. Axelrod's book, Believer , looks back over his 40 years in politics as a strategist and before that a reporter and columnist for the Chicago Tribune . In one controversial passage, he recalls how Obama was "slightly irritated" by the concession call Mitt Romney, his 2012 opponent, made to the president on election night. Obama told Axelrod that Romney had congratulated him on getting out the vote "in places like Cleveland and Milwaukee" - a remark that Obama took to refer to black people. "That's what he thinks this was all about," Obama said at the time, according to Axelrod. Over the past week, Axelrod's account of the conversation has been fiercely disputed by former Romney aides, who have accused Axelrod of lying. "I did not lie," Axelrod said. "I reported what the president said when he got off the phone". The strategist reserves his harshest words in the book for those whom he accuses of whipping up underlying anxieties about race. He writes that "some folks simply refuse to accept the legitimacy of the first black president and are seriously discomforted by the growing diversity of our country. And some craven politicians and rightwing provocateurs have been more than willing to exploit that fear, confusion and anger." Axelrod specifically name-checks the "tea party" movement as having been enhanced by "deep-pocketed Republican oligarchs" for displaying an anger rooted in race. It was, he writes, "a deep-seated resentment of the idea of the black man with the Muslim name in the White House".