To understand the Republican Party's struggles to formulate a midterm agenda, just look at the political trajectory of Marco Rubio.
The senator from Florida, a potential 2016 presidential contender, has calibrated his positions with the prevailing political mood more effectively than any other Republican. He championed immigration reform last year when Republicans thought it was the key to the party's long-term political fortunes, only to now emphasize the Obama administration's unilateral approach in explaining why he no longer supports such efforts. Despite being a longtime foreign policy hawk, he broke with Sens. John McCain and Lindsey Graham so that he could join most other Republicans in denying the president's request to authorize force against Syria. And as a Jeb Bush protege, he supported statewide educational reforms setting high standards for schools, but came out against the Common Core curriculum when the conservative base revolted against specific federal standards.
Political reporters like to use the catch-all phrase "establishment" to describe the GOP's leadership class, but it's important to distinguish party leaders and big-money donors from the strategists who advise the campaigns. Rubio is a product of the latter—the party's influential consultant class. On paper, Rubio checks every box that political operatives pine for—he's young, Hispanic, telegenic, and clear-spoken on both domestic and foreign policy issues. And unlike many of his prospective rivals, he's been articulating his policy vision by focusing on the middle class with economic security, education reform, and classic American values arguments. Those also happen to be the issues swing voters cite as concerns.