Here is how John Edwards's careful courtship of the Service Employees has paid off: not only will Edwards get the endorsement of the relatively small, nurse-heavy Iowa SEIU affiliate today, he'll receive the support of nine other state affiliates, Democratic sources say.

Endorsements like this are momentum-drivers; they help caucus turnout on the margins, only, but provide campaigns with a fresh supply of volunteers and endless surrogates.

The two biggest: California, which has 656,000 members and Washington State, which has 103,000 members.

Other states include: Michigan (70,000 members), Idaho (400 members), Montana (500 members), Minnesota (28,000 members), Ohio (22,000 members), West Virginia (4,000 members) and Oregon (46,000 members).

The Edwards campaign interprets the SEIU rules to allow these SEIU affiliates to help them turn out caucus goers in Iowa, although they are limited largely to making telephone calls.

Also today, Barack Obama was endorsed by the Illinois State Council of the SEIU and the Indiana State Council, representing a total of 170,000 members.

And Hillary Clinton... has yet to be endorsed by New York's 1199, the largest local union in the world, which claims more than 300,000 members. That won't happen today.

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