Both states are overwhelmingly white, largely rural and have a greater share of residents below the poverty line and without college degrees than the nation as whole.
And, as she did in West Virginia,is expected to rack up a sizable victory in Kentucky's May 20 Democratic primary against front-runner , who is hoping to counter with a win on more favorable turf in Oregon the same day.
Clinton's track record gives her a strong advantage in Kentucky. Whites have favored Clinton over Obama by 55 percent to 40 percent, rural voters 51-43, and voters without college degrees 52-44 in exit polls from 26 competitive primaries.
Obama is strong among urban dwellers and rural blacks, giving him a fighting chance among voters in Louisville, the state's largest city, but little hope elsewhere, voting trends in other states indicate.
"Obama doesn't have much of a natural constituency in Kentucky," said Michael Baranowski, a political scientist at Northern Kentucky University. "Really, everything works in Clinton's favor."
One difference between the Rust Belt states that Clinton has won recently - Ohio, Pennsylvania and Indiana - and Kentucky is that the Bluegrass State has mostly benefited from trade with China.
Kentucky farmers grow tobacco for Chinese smokers. Distillery workers produce the world-famous bourbon whiskey, including Maker's Mark and Wild Turkey, that Chinese drinkers relish. In all, the state does more than $300 billion worth of business with China each year, according to the Kentucky World Trade Center in Lexington.
Clinton and Obama have appealed to blue-collar workers with promises to reopen trade agreements to include stronger labor and environmental protections. But Clinton has taken a harder line on China, suggesting that Bush should not attend opening ceremonies for this year's Olympic Games because of human rights abuses.
A record 2.8 million Kentuckians are registered to vote in the primary election. Of those, 1.6 million are Democrats. And, despite the close presidential primary, the number of new registered voters hasn't skyrocketed. In the past six months, 16,000 people have registered, 13,000 of them as Democrats.
Records from the Kentucky Board of Elections show that 53 percent of the state's registered voters are women, a demographic that has played in Clinton's favor in other states. Kentucky doesn't track party registrants by race, but blacks make up only 7.4 percent of the state's population compared with 12.4 percent nationally - a far smaller minority voting bloc than in other Southern states carried by Obama.
And Kentucky voters are slightly older than voters nationally, another advantage for Clinton.
Clinton has won the endorsement of three of Kentucky's Democratic superdelegates. Obama has been endorsed by two, both Democratic congressmen representing the state's two largest cities. Three other superdelegates remain undecided.
Both candidates have opened campaign offices across the state. Clinton has campaigned in Kentucky, as have her husband and daughter. Until this week when he held a huge rally in Louisville, Obama hadn't visited the state this year, but he's running ads in all Kentucky TV markets.
Political scientist Kendra Stewart at Eastern Kentucky University said Kentucky voters are interested largely in the same issues as their counterparts across the country - the economy, fuel prices, health care and Iraq. Kentuckians struggle with joblessness, especially in the impoverished mountain communities in the eastern half of the state. That population is also hit hardest by the price of gasoline, and more likely be without health care benefits.
Steve Earl, a union representative for the United Mine Workers of America, is convinced that the economy is the overriding issue, and that voters will make their decision based on who they think is best able to bring change.
"People are struggling across the state," he said.
Economic policy and energy policy are intertwined in Kentucky, where the coal mining industry employees 21,000, according to the National Mining Association.
Both Obama and Clinton have rallied environmentally-minded voters in other states with their promises to develop windmills, solar power and other renewable energy sources and order mandatory reductions in greenhouse gases from power plants to counter global warming.
It's a stance that would seem to target coal, which produces half the country's electricity but also nearly 2 billion tons of carbon dioxide, the leading greenhouse gas, each year.
Instead, "clean coal" - which environmentalists say is a contradiction - has become the mantra of both candidates.
On fuel prices, Clinton has advocated a summer gas tax holiday - an idea Obama opposes and one that has been widely panned by a range of influential economists.
With two large military installations - Fort Campbell and Fort Knox - Kentucky also has a big stake in the war in Iraq, but the issue may not be huge in the state's primary, Stewart said. Clinton and Obama have taken similar stands, each calling for withdrawing troops from Iraq.
Stewart said Clinton's support among churchgoers in other states bodes well for her in Kentucky. Clinton has done especially well among Catholic voters, which, Stewart said, could help her offset Obama's support among blacks in Louisville, one of the state's strongest Catholic communities.
One of the things that make Kentucky politics exciting, Stewart said, is its unpredictability.
"Kentucky's so unique since we don't have a solid identity," she said. "We aren't for sure a southern state, and we're not a midwestern state. So, at times, it can be difficult to make these generalizations."
By Roger Alford