Rep. Joe Donnelly soared down U.S. Route 41 in Indiana in his navy Jeep on the two-hour drive from Terre Haute to Evansville. It was the evening of Oct. 3, and after 18 grueling months of campaigning, Donnelly had received his best poll numbers yet that morning. Flanked by cornfields and Cracker Barrels, he believed he had finally put away his opponent, state Treasurer Richard Mourdock.

An hour later, Donnelly felt sick to his stomach. On the car radio, he heard the president blow his first debate — and, by proxy, Donnelly’s unprecedented lead. He knew the math: It’s nearly impossible for a Democratic candidate to win statewide if the president loses Indiana by more than a dozen points.

But Donnelly’s circuitous road to the Senate was far from over. He started the cycle as an afterthought on Democrats’ difficult Senate map, spending miserable hours fundraising in the windowless basement of his party’s headquarters. He ended the cycle as one of the Democrats’ all-stars, picking up a Senate seat in a state as red as Hoosier crimson.

Maybe Donnelly got lucky. His detractors and even some supporters argue the congressman would not have won if not for Mourdock’s inarticulateness. Undoubtedly, the Republican nominee’s tearful proclamation that pregnancy from rape is something “God intended” changed the race.

But Mourdock’s comments reverberated, in part, because Donnelly’s team was in a position to take advantage of his opponent’s rhetorical misstep. Mourdock’s team never stopped running a Republican primary campaign — and that, exacerbated by the candidate’s infamous comment, cost him the race.

Basement Bottom

December 2010 marked a low point for Hoosier Democrats. They had just about wiped out in the midterm elections. Donnelly’s friend, Rep. Brad Ellsworth, D-Ind., lost his Senate bid by a whopping 15 points. Democratic Rep. Baron Hill lost by double digits, and Donnelly survived re-election by less than a point.

In the wake of those losses, longtime state Democratic Party Chairman Dan Parker summoned more than a dozen Democratic candidates, including Donnelly, Ellsworth and Hill, to lunch at a seafood house on Indianapolis’ west reservoir that month. Parker wanted an open discussion about upcoming statewide races and, above all, to avoid the kind of primary that plagued his party’s aspirations before.

“I don’t know who you are, but one of you is running for Senate and one of you is running for governor,” Parker told the group gathered out of eyesight in the basement’s private dining room at Rick’s Boat Yard.

There were subsequent meetings every few weeks — sandwiches at a downtown Indianapolis law firm and pizza at the party headquarters. As each encounter went by, candidates pulled their names out of the ring.

By spring, Donnelly didn’t have any competition to take on a race some viewed as a quixotic bid to stay in Congress. Republicans redrew his congressional district, making it even more difficult for a Democrat to retain.

“Donnelly had to slug it through in 2011 and not have good fundraising quarters,” Parker recalled. “The strategy was, we have to survive until May.”

During that long year, Donnelly crisscrossed the state for Jefferson-Jackson dinners, preferring county roads and a time-consuming navigation system his staff refers to “Joe-PS.” En route to Plymouth, Donnelly ordered his aide to short-stop the car so he could usher a snapping turtle across the two-lane road with a cardboard box. He was already late.

For Donnelly, the GOP primary moved at tortoise speed, but it helped him that the focus was entirely on Mourdock’s bid to unseat six-term Sen. Richard G. Lugar.

Mourdock stumbled frequently, also posting terrible fundraising numbers and irking national conservatives at the start. But Lugar’s campaign fared worse. The octogenarian had not run a competitive race in three decades — and it showed. On May 8, he lost his primary by nearly 20 points.

The Infliction

Mourdock took a victory lap on cable television after his primary win in May. The race drained the former geologist’s bank account, and his team believed he could bank $30,000 to $40,000 per appearance in fundraising.

During that money-making media tour, Mourdock halfheartedly teased in a MSNBC interview, “To me, the highlight of politics is to inflict my opinion on someone else.” Democrats repeated this clip ad nauseam throughout the general election. They defined Mourdock as an uncompromising extremist in one of the cycle’s few examples of Democrats outspending GOP outside groups over the summer.

More disappointing for Mourdock’s team was that his fundraising didn’t improve much in the first couple of months of the general election. A divisive primary left many former Lugar supporters — some of the state’s biggest GOP donors — on the sidelines.

“I don’t know what’s worse: Hyperpartisans for Richard Mourdock blaming everyone but themselves for the loss, or hyperpartisans for Richard Lugar saying, ‘I told you so,’” said Chris Faulkner, a Republican consultant from Indiana. “Neither attitude is helpful.”

Several members of Mourdock’s team did not return interview requests for this story. But it’s clear some of their emotions are still raw: Mourdock’s campaign spokesman, Brose McVey, simply replied via email, “Not ready to talk yet.”

But it’s clear the campaign made two strategic errors over the summer: Mourdock never bridged the gap with Lugar’s supporters, and his rhetoric never graduated from the primary. Meanwhile, Donnelly had the opportunity to run a general election campaign from the start.

“It’s the [Frank] O’Bannon Plan,” said Donnelly, referring to the late Democratic governor of Indiana. “We got about 15 percent of Republicans, got the majority of independents, [in addition to] Democrats. It’s not complicated. You reach out to everybody.”

‘God Intended to Happen’

Despite Mourdock’s foibles, he entered the final debate with an advantage. But the entire race changed in a single, convoluted sentence.

“And even when life begins in that horrible situation of rape, that it is something that God intended to happen,” an emotional Mourdock answered to an open-ended question on abortion.

Immediately, operatives on both sides separately questioned, “Did he just say that?”

Republicans had practiced this question with Mourdock. The National Republican Senatorial Committee brought in one of the party’s top debate coaches, Brett O’Donnell, to prepare him. (O’Donnell declined to comment.)

Ironically, Donnelly never practiced that question once, according to his sparring partner in mock debate practice, Bill Moreau.

“The one thing we didn’t work on was the abortion question,” said Moreau, a former chief of staff to former Democratic Sen. Evan Bayh. “There was absolutely no need to. Joe Donnelly has had the same position on abortion since I first met him in 1988.”

After the debate, Mourdock entered the green room expecting high-fives from his aides. Dumbfounded, he spent the next days explaining and apologizing for his comment instead.

Donnelly had to double-check with his aides before he spoke with reporters about the comment. He didn’t realize the full extent of Mourdock’s words until his college roommate called him from Chicago the next morning. He had just seen Mourdock’s awkward phrase lead the newscast on “The Today Show.”

“I almost didn’t fully comprehend it,” Donnelly said. “I thought I had heard that, but I wasn’t sure. I didn’t want to say anything right at that point. If I was wrong, it wouldn’t have been appropriate.”

The Worst Possible Time

It’s impossible to know whether Donnelly won because of Mourdock’s mishap. Democrats estimate it cost the Republican 4 points in the polls, and Donnelly won the race by nearly 6 points.

But Republicans have no doubt he lost the race because of it.

“He was literally 12 minutes away from being a U.S. senator,” said an operative who worked on Mourdock’s race who declined to be named. “Every other key indicator in that race was going the right way until 48 minutes into the debate.”

The incident hit Mourdock’s campaign at the worst possible time: Too late for him to recover.

Democrats blasted his words all over the state. Voters, especially moderate Republican women around Indianapolis, were already looking for a reason not to vote for Mourdock, or to stay out of the race completely.