FOREST, Miss. – Mississippi Sen. Thad Cochran appeared at a Raytheon industrial plant Thursday afternoon, shaking hands with workers as they changed shifts and sounding upbeat about his chances in the three-week sprint to decide the state's Republican Senate nomination, in spite of a nagging bout of laryngitis and fierce opposition from tea-party activists.

U.S. Sen. Thad Cochran, R-Mississippi, speaks on stage during a pre-election day rally at the Mississippi Agriculture and Forestry Museum in Jackson, Miss., on Monday, June 2, 2014 (AP Photo/The Clarion-Ledger, Joe Ellis)

Cochran's appearance, his lone public stop of the day, reflects his campaign's strategy ahead of the June 24's runoff election: emphasizing his ability to usher federal dollars and business to Mississippi and shrugging off his hardline challenger's boasts of conservative purity.

"I've still got little touches of it," Cochran, 76, said of the throat ailment as he stood, jacket off, in the sweltering heat outside the facility, which he said he helped bring to the state decades ago. "I'm kind of hoarse sounding and don't have a lot of volume, so thank goodness for microphones."

On Tuesday night, Cochran did not address his supporters after he came in a narrow second to state Sen. Chris McDaniel in the GOP primary's first round of balloting, leading many in Mississippi politics to wonder if the longtime lawmaker was wary of a fighting a drawn-out battle. Cochran insisted that it was illness that kept him from speaking. When told the Club for Growth, a high-powered conservative group, was calling on him to step aside, he shook his white mop of hair and chuckled.

"Whoa," Cochran said. "That's pretty dramatic. They can relax about the dropping out. I have no intention of dropping out."

Cochran said his playbook for the coming weeks is to return to places where he has deep ties and running a campaign like he has in six previous Senate races, underscoring his links to the business community and his compassion for the rural voters who look to him to secure federal funding for Mississippi from his senior perch on the Senate Appropriations Committee. Trailing Cochran was Stuart Stevens, a Mississippi native and Cochran's strategist who advised Mitt Romney's 2012 presidential campaign.

Asking Democrats and independents to back him, Cochran said, is part of his plan. Under election law in Mississippi, which does not register voters by party affiliation, any voter can cast a ballot in the June 24 runoff -- as long as they did not vote in this week's Democratic primary.

"I'll be doing similar to this," Cochran said, gesturing toward the heavy trucks rolling by and the stream of employees coming through the door. "I'm not trying to overdo do it, but I feel like we've struck the right balance."

As Cochran toured Raytheon, which sits 47 miles east of the state capital, he was warmly greeted by a number of African Americans, a voting bloc Cochran said he hopes turns out strong for him later this month. In a state with a rocky history of race relations, Cochran noted he has long been an advocate for voting rights.  According to the Census Bureau, Mississippi's population is 38 percent African American. Ahead of Tuesday's primary vote, a group chaired by a black pastor, "All Citizens for Mississippi," paid for pro-Cochran advertisements that ran in two newspapers, and passed out pamphlets.

McDaniel's campaign was mostly quiet Thursday as he dealt with news, first reported by the Jackson Clarion-Ledger, that three people, including one of his staffers, was locked in the Hinds County courthouse in the wee hours of Wednesday morning, raising questions about potential election meddling. McDaniel did not make any appearances and his upcoming schedule has not yet been released. In a statement, McDaniel's spokesman, Noel Fritsch, said the trio under scrutiny was sent by the campaign to observe the count and entered through an "open door after being directed by uniformed personnel," and were later locked inside, playing down suspicions of political foul play.

At McDaniel's campaign office in Flowood, Miss., volunteers spent the morning organizing flyers and hanging signs. When one supporter began to express concern about the courthouse episode, they were quickly led to the back after an aide realized I was there.

Cochran said he read about it the incident in the morning and called it a "really bizarre" moment in a campaign that has been roiled by controversies, such as when a McDaniel supporter broke into a nursing home and took a photograph of Cochran's bedridden wife, Rose. That person and three others have been arrested and charged with conspiracy.

"Don't reward that behavior," Cochran said, sounding hopeful but not entirely confident that Mississippi voters would do so.