Once you get past the fundamental qualifications of basic honesty and credibility, there are three ingredients, it seems to me, that make for a successful conservative leader.
The first (this should be obvious) is a solid conservative political philosophy. The second is charisma (like it or not, Americans prefer charismatic candidates, and it has become mandatory for the modern era).
Last (and perhaps most elusive) is the ability to effectively articulate a conservative message. This is not to say candidates must be pointy-headed intellectuals, but a leader must be able to persuasively present a serious argument for their ideas.
To be sure, there are many leaders and candidates out there who bring two of these qualities to the table, but very few can pull off the hat trick.
Marco Rubio's election Tuesday is vital because he is one of the few conservative leaders on the horizon who combines all three qualities. He could be president some day. That's why Democrats were so desperate to get Kendrick Meek out of the race and try to help Gov. Charlie Crist's independent bid. Rubio's election is about far more than just electing a Republican senator...
(Matt Lewis, "Why Marco Rubio's Win Is the Most Important One for Conservatives," Politics Daily)