How We Got To This Point: The Residency Issue: This was a crippling blow to Lugar. But it didn't have to be. The senator, who lives in northern Virginia and in 1977 sold the Indiana House where he is registered to vote, began to face scrutiny about his address early in 2012. A Daily Caller story in late January prompted further scrutiny from the local media and from opponents. Lugar would get legal cover the following month from Indiana Election Commission, which came on the heels of a non-binding opinion from the Indiana Attorney General's office which also indicated Lugar was not doing anything wrong. But the story dominated the headlines in the Indiana papers for months, and his campaign was simply unable to turn the page, politically, on a story that gave his opponents endless fodder to paint him as out of touch with Hoosier State voters. Lugar's own team didn't help his cause, doing things along the way like comparing Lugar's residency situation to military personnel. "Every time any little issue in terms of politics, procedure, process or policy came up, it seemed like there was a Lugar stumble," said Ed Feigenbaum, the editor of the Indiana Legislative Insight newsletter. Outside Groups rallied around Mourdock ... Eventually: Throughout much of 2011, Mourdock's campaign hardly looked like one that had the potential to match Lugar's resources. His fundraising was weak and he didn't do enough to get outside groups off the sidelines to help him. That changed in February, when the Club For Growth decided to back him in the race. Since then, the group has assailed Lugar with negative ads with hundreds of thousands of dollars behind each buy. The Club has been selective this cycle, picking and choosing where it wants to play across the Senate map (it has largely stayed out of Utah, for example) so it was no sure thing that the group was eventually going to rally behind Mourdock. Mourdock Was (Barely) A Strong Enough Opponent: No one in Indiana is going to credit the Mourdock team with running a deft campaign. Often the cause of his own negative headlines in 2011 and hamstrung by a lack of money, Mourdock didn't exactly resemble a blue chip recruit throughout much of 2011. But given Lugar's problems, he didn't have to be. He made the race about Lugar and stuck to that message like glue. Late in the race, when the Lugar team worked furiously to raise doubts about Murdock's readiness to be a senator, he remained steady, not generating the kind of eleventh hour headlines that can sink campaigns when they are under maximum scrutiny. Lugar and Mourdock debated just one time during the entire campaign. That showdown, from which Mourdock emerged no worse for the wear, was an important point in the campaign. "Mourdock deserves a great deal of credit for a very strong debate performance when he made it clear to Hoosiers he was up to the task of representing (them) in the U.S. Senate," Feigenbaum said. Timing Is Everything: This race began to heat up just as the sun was setting on the GOP presidential race. Mourdock himself told Hotline On Call that Rick Santorum's departure from the presidential race meant his race would be the new hot ticket on the public's radar. He was right. Santorum's exit also meant more practical advantages for Mourdock. Without Mitt Romney's troops on the ground in Indiana turning out voters (who would also tend to support Lugar), Lugar stood to gain little peripheral support. One more word about timing: Whether it was the attacks on Murdock's record, the responses to the residency issue or other parts of his record that came under scrutiny, Lugar always seemed a step behind.