Secretary of State Elaine Marshall says it would take serious cash, $15 million or so, to mount a serious challenge to U.S. Sen. Richard Burr next year.

Marshall, a Democrat, told Hotline on Call, a National Journal blog that she is planning a second trip to Washington to meet with party officials and donors to "test the waters"

"Let's face it, it's hard to run a campaign in North Carolina," Marshall said. "You can't do it without some outside money. So these are the things I'm assessing."

Marshall has joined a Facebook group urging her to run.

"Elaine Marshall has never shied away from a challenge," the page explains. "Join our group to urge Secretary Marshall to run for U. S. Senate." 

Previously: Potential candidates for Senate 2010.