The Arkansas Senate primary between Sen. Blanche Lincoln and Lt. Gov. Bill Halter is acting as a testing ground for express advocacy advertisements allowed under the Citizens United Supreme Court ruling. The first of these advertisements are coming from labor unions and environmental groups largely in support of Halter’s run to unseat Lincoln. Mother Jones reports on the labor union ads:

In recent weeks, the American Federation of State, County, and Municipal Employees (AFSCME) and the AFL-CIO have begun to use the new Citizens United rules to promote their preferred candidates in closely fought contests, such as Lt. Gov. Bill Halter’s challenge to Sen. Blanche Lincoln in Arkansas’ Democratic Senate primary, and the special election in Pennsylvania’s 12th congressional district, which Democrat Mark Critz won in mid-May. In a television ad that started airing late last month, AFSCME whacked Lincoln for moving her family permanently to Washington and taking money from corporate interests. “Blanche Lincoln packed up and left us years ago. Maybe it’s time for us to send her packing, for good,” the ad concludes. … AFSCME also ran a slew of radio ads in Arkansas made possible by Citizens United. Funded by soft money, the ads urged voters to “say no to Blanche Lincoln,” “vote no on Blanche Lincoln,” and “vote for Bill Halter,” as well as another TV ad that suggested that “it’s time for Arkansas to let [Lincoln] go.”

Another express advocacy ad came from the League of Conservation Voters. The ad ties Lincoln to former President George W. Bush and his energy policies and asks the viewer to, “Send Blanche Lincoln packing”: At first glance, these ads do not seem much different from your normal campaign advertisement. The important change is in the message at the end of the ad. Mother Jones’ Suzy Khimm explains the change:

Before the Citizens United ruling, corporations, unions, and other independent groups could only run express advocacy ads if they were funded by political action committees, which are restricted to $5,000 donations each year from individuals—a category known as “hard money.” Now, those groups can use any funds for these campaign efforts—an unrestricted category called “soft money.” Because these groups typically have far more soft money than hard money on hand, this significantly increases their potential budget for advertising that directly attacks or supports a candidate.

Let me know in the comments if you’ve seen any other express advocacy ads like the ones run by AFSCME or League of Conservation Voters.