Last year, Comcast was lining up the Rev. Al Sharpton to lobby for its bid for NBCUniversal. This year, the cable news channel owned by NBCUniversal, MSNBC, is weighing whether to make him a daily television host.

The possible transition for Mr. Sharpton — from political influencer to television talent — highlights the complex relationships that can arise when cable news channels employ activists who take sides instead of journalists who don’t.

Mr. Sharpton, the president of the National Action Network, a civil rights organization, was one of the many activists and boldface names who agreed to support Comcast as it sought government approval for its takeover of NBCUniversal.

The Comcast chief executive, Brian L. Roberts, and the head of the company’s lobbying effort, David L. Cohen, met with Mr. Sharpton and other representatives of minority groups to talk about their bid early last year. That meeting, Mr. Sharpton said later, was the most important factor in his decision to support Comcast and urge the Federal Communications Commission to approve the NBC deal. Comcast then used the support of Mr. Sharpton and other civil rights activists to promote the proposed merger to government officials.