The American Federation of State, County and Municipal Employees voted Tuesday to officially endorse President Obama in the 2012 election.

Union officials have already said they planned to spend upwards of $100 million to help Obama win reelection, so the endorsement itself is not a surprise.
But Obama has had a rocky relationship with labor and other facets of his political base, and having the full-throated and unequivocal support of the AFL-CIO’s largest union could add a spark as the reelection campaign works to rebuild its grassroots machinery.

AFSCME officials said their ground-level organization in several presidential battleground states is finely-tuned following battles over public-sector worker bargaining rights in Ohio and Wisconsin.

Tuesday’s vote was so important to Obama’s team that campaign manager Jim Messina attended the meeting. He told the AFSCME board the union’s backing “demonstrates that its workers know President Obama is the only one willing to make the hard choices.”

   Union officials said the endorsement could help revive enthusiasm for Obama, despite his failure to push the Employee Free Choice Act, known as “card check,” which would have made it easier for unions to organize. Some also felt the president was not aggressive enough in his support for public workers in their battles with GOP governors. And a number of labor leaders have bitterly criticized the White House for its courtship of corporate America over the past year, with some unions picketing a speech that Obama delivered earlier this year at the U.S. Chamber of Commerce.

    A poll of AFSCME’s 1.6 million members found they overwhelmingly backed Obama, with about a quarter expressing support for a Republican opponent.

   Tuesday’s vote by the union board was unanimous.

   “Obama’s been criticized for not doing enough for his base,” Larry Scanlon, AFSCME’s political director, said in an interview. “So you always worry about the mood of your membership. But the depth of support in the room today for Obama surprised even me.”

   The endorsement comes as Obama delivers a speech today in Kansas focused on highlighting the wealth gap in the country. Democratic strategists see that tension as a key to next year’s election, and they have been hammering the GOP as the party of the wealthy.

   AFSCME President Gerald McEntee, adopting language of the Occupy Wall Street movement, said Tuesday: “ “President Obama is the only choice for the 99 percent.”