Rep. Michele Bachmann’s prospective 2012 campaign appears increasingly set on a collision course with former Alaska Governor Sarah Palin.

The coming confrontation is being driven by a belief in Bachmann’s camp that the same grassroots, conservative primary voters and caucus-goers may have to choose between the two women—and that they will choose Bachmann if she presents herself as a more seasoned, reliable, and serious conservative than her high-profile rival. The apparent effort to draw distinctions broke into the open Tuesday when her new top strategist, Ed Rollins, dismissed Palin as “not serious” in a radio interview.