WASHINGTON -- With Alison Lundergan Grimes down in almost every poll in a tight race against Senate Minority Leader Mitch McConnell, her success may hinge on whether she can bring Paducah, a small city more than three hours west of Louisville, into her camp.

Paducah has long been a lynchpin in McConnell's simple but effective "west of Interstate 65" strategy. McConnell, who started his career as a political moderate, has pursued a campaign strategy that depends on winning over the counties west of I-65, the highway that bisects Kentucky from Louisville in the north to the Tennessee border in the south. McCracken County, which covers Paducah, didn't swing McConnell's way when he was first elected to the Senate in 1984. But the county soon fell into McConnell's column and has remained there ever since.

McConnell has relied on a Cold War-era uranium facility for the core of his support. The plant helped put Paducah on the map, and the town's identity has long been tied to it. Paducah called itself "The Atomic City" during the postwar years, and murals celebrating its 1950s heyday still line the town's floodwall along the Ohio River. By the mid-1980s, however, the Paducah Gaseous Diffusion Plant had become a relic. As similar facilities were shuttered in other states, McConnell pitched himself as the one man who could work the Senate to keep the plant open.

This is the first campaign in which the plant could be a liability for him. After decades of decline, it finally shut down this year, when the last of its more than 1,000 operators were laid off.

In a recent campaign ad, Grimes used the Paducah plant as a backdrop. "You want to know the difference between Mitch McConnell and me?" she says directly into the camera. "Just look at the Paducah Gaseous Diffusion Plant ... He'd just show up at election time and say he'd saved the plant. Now it's shutting down anyway."

Grimes has visited the county at least eight times since launching her campaign, pounding away at Paducah's economic trouble. The city's 7.8 percent unemployment rate is above both the state and national rates, and was nearly 10 percent as recently as February. The old plant workers may be swayed by Grimes' message.

"They are taking a different view of the senior senator," said Jim Key, vice president of the local steelworkers union to which the plant workers belonged.

Paducah isn't a hotbed for hardline anti-government conservatism. Mayor Gayle Kaler praises McConnell for delivering federal dollars to her beleaguered town. McConnell's pitch to the town has relied on the same -- keeping the plant open with federal money, and helping to start a program that provides free health care to workers who had been poisoned working in the facility's hazardous conditions.

In 2013, The Huffington Post outlined how McConnell ignored the toxic conditions that hurt plant employees and polluted the surrounding wells and waterways. In her ad, Grimes cited the story in making a similar point. "Mitch did nothing about the radiation problems for over a decade while workers got sick," Grimes says in her ad.

McConnell actually went much further. The senator voted in 1988 to prevent sick workers from seeking legal redress for being poisoned. The McConnell campaign did not respond to a request for comment.

Republicans know McConnell is vulnerable here. The status quo isn't good, and McConnell has been the senator for 30 years. So they're doing all they can to pin the town's economic doldrums on Obama, who is wildly unpopular in the state -- and to tie him to Grimes and any Democrat they can.

Voters are even getting mailers from multiple GOP-affiliated groups attempting to tie little-known state Rep. Gerald Watkins (D-McCracken) to Barack Obama. The flyer claimed "a vote for Gerald Watkins is a vote for Obamacare." The mailers can be seen here and here.

Watkins, who teaches at a community college, thinks the attempt to associate him with the president comes from a single meeting he had with then-Sen. Obama in 2006, after which he told a reporter he thought Obama was intelligent. Watkins told HuffPost that the flyer's Obamacare claim is "ridiculous." "It's a federal law," he said. "I'm at the state level."

Watkins thinks the plant's closure could be a problem for McConnell. "It could very well impact the election, because he's always championed the workers there and helped keep the plant open for all these years," he said.

At a recent visit to Paducah, Grimes brought former President Bill Clinton to stump on her behalf at a campaign event in the McCracken County High School gym. Principal Michael Ceglinski, who attended the event, said the transformation of his gym into a political pep rally was amazing, a temporary spark amid the plant layoffs that he said have affected the school.

Ceglinski said some of his students had to leave the school when their parents were laid off and had to move away. "Some of my closest friends have lost their jobs there, and you struggle with them," he said. "You hurt for them and their families. You go through it emotionally."

The battle for Paducah may hinge not on Grimes' economic message but on the city's nostalgia for Clinton's economic record. Democrats have cited Clinton's appearance on the campaign trail as a key factor in whatever success Grimes may have in her own "west of I-65" strategy. Clinton, who carried Kentucky twice, is one of the most popular political figures in the state. Even Paducah's Republican mayor admitted to admiring Clinton.