The Service Employees International Union (SEIU) is apparently the first outside group to begin running an independent ad campaign for a favored statewide candidate.

In this case, it’s Missouri’s likely Democratic nominee for governor, Attorney General Jay Nixon.

According to the release:

The cost of the ad buy is $450,000, the largest independent ad buy focused on the general election to date.  Beginning Tuesday morning, Missouri voters will see the ad for the next two weeks on broadcast and cable TV stations throughout the state. 

Such an ad campaign, the costs of which won’t show up on Nixon’s campaign reports, cannot be coordinated with his operation. Otherwise, the independent spending runs afoul of Missouri campaign-finance law.

By the way, the ad refers viewers to Nixon’s old domain name: nixonforgovernor.com. Still checking to see if it redirects traffic to his current site, Jaynixon.com.

(UPDATE: The old site does redirect traffic to the current one. One Democratic wag said the use of the old domain name verifies that SEIU isn’t coordinating with the Nixon campaign.)

Here’s the ad: