New York Magazine feature writer John Heilemann takes up the debate over whether Sarah Palin and Michele Bachmann could coexist in an already crowded field. But Heilemann is less interested in the prospect of the two siphoning off votes from one another than in the powerful challenge one or both could pose to the Republican party machinery, particularly given the lack of mainstream candidates with the same ability to energize voters.

The prospect of their entry into the fray should be causing queasiness for the Establishment big three of Romney, Pawlenty, and Jon Huntsman, none of whom has demonstrated even the capacity to generate faint sparks, let alone light a fire in the hearts of the Republican faithful, Heilemann writes.

He notes that in the past, GOP candidates who were popular amongst evangelicals didn't appeal enough to the broad party base to be relevant. In 2012, he contends, things could be different: the fusion of the Tea Party, insofar as it is a unified movement, and evangelical voters has created a large, passionate constituency. Palin and/or Bachmann, doyennes of the burgeoning Tea Party movement who are beloved for their populist appeals and faith-informed leadership, thus represent a potentially formidable threat.

If nothing else, Palin's cat-and-mouse game with a media eager to cover every aspect of her ostensibly non-political East Coast tour demonstrates her sustained ability to command the spotlight and to invigorate . Bachmann is a native Iowan and should appeal strongly to Iowa's traditionally influential evangelical bloc, giving her a potential edge in a crucial early primary. It is possible that Palin won't run, or that Bachmann will fizzle early; but as Heillemann notes, they should not be ignored.