Chris McDaniel lost the runoff election for Mississippi's Republican Senate nomination just over a week ago. But it's only after that (apparently unexpected) loss that his campaign really kicked into high gear.

"Thanks to illegal voting from liberal Democrats, my opponent stole last week’s runoff election, but I’m not going down without a fight," reads a fundraising e-mail sent by the McDaniel campaign Wednesday. "I know exactly how long and frustrating court battles can be, but I believe this will be worth it. There is too much at stake to back down from this fight."

Emphasis in the original, although that little bit of bolding doesn't quite capture the frustration of the campaign.

Each phase of McDaniel's campaign has been unorthodox. In early June, he led incumbent Sen. Thad Cochran by a tiny margin, but not enough to avoid that runoff. That was phase one. Then the runoff, which was unprecedented in Mississippi and, like the primary, was bolstered at unprecedented rates by outside spending. And now phase three: the challenge.

At first, McDaniel's campaign focused on two legal strategies that it hoped could invalidate votes from those "liberal Democrats," also known as "black voters." Neither was likely to bear fruit, as we noted over the weekend. But the anger from McDaniel supporters, captured nicely by Slate's Dave Weigel, was never likely to be mollified by arguments dependent at law books and spreadsheets. The idea that overwhelmingly Democratic black voters boosted Cochran has merged with frustration at the Republican establishment to form an increasingly energetic opposition to last week's results, not necessarily moored to facts.

On Monday, a bombshell allegation from conservative blogger Charles Johnson: The Cochran campaign was allegedly handing out cash to buy votes in black communities. Johnson writes:

"They said they needed black votes," said Reverend [Stevie] Fielder on the phone. He says [Cochran staffer Saleem] Baird told him to "give the fifteen dollars in each envelope to people as they go in and vote. You know, not right outside of the polling place but he would actually recruit people with the $15 dollars and they would go in and vote." Fielder said he received thousands of dollars in envelopes from Baird and distributed them accordingly. Fielder also says he went to the campaign office on another occasion to pick up $300 in cash and was among a room full of people who were doing the same thing he was.

The story gained traction instantly among conservatives. FreedomWorks, which invested heavily in McDaniel's candidacy, called for a federal investigation.

Fielder's charge doesn't hold up, though. He told Johnson that he'd turned "hundreds" of people out to vote, that he'd handed out 5,000 to 10,000 in either envelopes or dollars (the tape isn't clear) to voters to go to the polls. (If it was 10,000 envelopes each with $15, that's $150,000 -- an amount that would comprise 3 percent of Cochran's spending in the primary and runoff.)

In Fielder's home county, Lauderdale, on the eastern edge of the state, turnout was up 24 percent between the primary and the runoff -- slightly under the statewide average. Over two thousand more people came out to vote, but the margin of victory for Cochran was basically the same between the two elections: 56.04 percent versus 56.41. If Fielder handed out 5,000 envelopes with $15 each -- or even just $5,000-$10,000 -- the Cochran campaign didn't get much for his work.

In the Jackson Clarion-Ledger, a spokesman for the Cochran campaign explained that Fielder had been paid by the campaign: to do get-out-the-vote work. Campaigns frequently hire staff to help as Election Day approaches, knocking on doors or phoning voters to remind them to vote. Earlier this month we looked at how political parties are staffed; the Democrats intend to eventually have 4,000 people working by the time Election Day rolls around. But hundreds of them will only be on payroll for those last few days, as Cochran's camp says Fielder was. (Which may explain the "room full of people" Fielder saw: others hired for short-term GOTV work.) In fact, Fielder was supposed to have gotten $600, but "he never completed any work for the second $300. He never provided any names and addresses of people he said he was getting," spokesman Jordan Russell told the paper. Fielder did get some additional money -- for the interview with Johnson, according to his story. It's not clear how much.

Conservative backers of McDaniel added another new front on Tuesday. True the Vote, a group focused on election integrity, filed a lawsuit against Mississippi state leaders calling for independent verification of runoff votes. McDaniel's campaign quickly e-mailed a statement of support. Money raised by the campaign (from, for example, the first e-mail cited above) would go into a fund to pay legal costs associated with challenging the election, McDaniel spokesman Noel Fritsch confirmed to The Post by e-mail.

The bar for victory in this third phase of the campaign is different. "We don’t have to prove that we have 7,000 [invalid] votes," Fritsch told the Daily Caller. "[A]ll there needs to be is enough doubt about the election, and we’re confident about that." That murkier goal, the campaign could conceivably reach.

Talking to The Post by phone, Cochran campaign adviser Stuart Stevens had a different perspective. McDaniel "ran a bizarre, eccentric campaign," he said. "In the runoff, he didn't work particularly hard. He didn't get off his butt. He didn't show up for events."

Stevens continued. "He lost. And because he lost, he wants to say it wasn't fair."