As a perennial swing state and one that yields 18 electoral college votes, Ohio has long been coveted territory for U.S. presidential candidates who pour piles of cash every election cycle into wooing its voters. Since the 1860 election of Abraham Lincoln just three presidents, and no Republican contender, have gone to the White House without winning the "Buckeye State." During this year's Republican party primaries, Donald Trump's pro-coal mining, anti-free trade message resonated with many of the state's 7 million voters, especially in southeast Ohio communities facing high unemployment. REUTERS/Shannon Stapleton SEARCH "BATTLEGROUND OHIO" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY Matching text: USA-ELECTION/OHIO ?