Iowa ophthalmologist Mariannette Miller-Meeks had come to Washington, D.C., many times since 2000 to talk to members of her state’s Congressional delegation about health care. But during an April 2007 visit, she caught a fever for Capitol Hill. Miller-Meeks and other doctors met with her new Congressman, Democrat Dave Loebsack, who upset longtime Republican Rep. Jim Leach in the 2006 election. Miller-Meeks, a Republican and a past president of the Iowa Medical Society, disagreed with her new Representative’s views on health care, and a thought occurred to her as she crossed to the Senate side with a group of Iowa...