President Barack Obama said on Tuesday the Bush administration had tried to undermine organized labor and he assured U.S. labor leaders they would always have a "place at the table" under his presidency. "We need to level the playing field for workers and the unions that represent their interests," Obama said in prepared remarks for a video address to the executive board of the AFL-CIO, the largest U.S. labor federation, meeting in Miami. Obama, who won strong backing from trade unions in his Democratic presidential campaign, said there could not be a strong middle class, the focus of his economic...