ORLANDO, Fla. (AP) - The AFL-CIO is endorsing President Barack Obama's re-election bid and says it will mount a big door-to-door effort for Democratic candidates to counter the flood of outside money that conservative groups are pouring into the campaign.

The labor federation said Tuesday its strategy is to spend less money on political parties and candidates this election cycle and place more emphasis on old- fashioned, get-out-the-vote shoe leather.

AFL-CIO officials say up to 400,000 union members will be manning phone banks and knocking on doors to persuade voters to support federal, state and local candidates.

A 2010 Supreme Court case allows union campaign workers to visit the homes of any voter, not just those of union members. The same ruling allows corporations and unions to spend unlimited cash in support of candidates.