At least two pollsters who worked for Democratic Presidents think so. Patrick Caddell and Douglas Schoen at the Wall Street Journal wrote:
"When Harry Truman and Lyndon Johnson accepted the reality that they could not effectively govern the nation if they sought re-election to the White House, both men took the moral high ground and decided against running for a new term as president. President Obama is facing a similar reality—and he must reach the same conclusion.
"He should abandon his candidacy for re-election in favor of a clear alternative, one capable not only of saving the Democratic Party, but more important, of governing effectively and in a way that preserves the most important of the president's accomplishments. He should step aside for the one candidate who would become, by acclamation, the nominee of the Democratic Party: Secretary of State Hillary Clinton...."