CINCINNATI — Ohioans are again getting plenty of attention in the presidential race’s final weeks.

After a lull last month, high-level campaigning has accelerated in the perennial battleground state. Republican Donald Trump campaigned here Thursday, while President Barack Obama and former president Bill Clinton followed Hillary Clinton’s return to the state earlier in the week with two Ohio scheduled campaign stops each.

The state’s role this year shapes up to be potential spoiler for Trump’s chances of reaching 270 electoral votes. While Clinton appears to have paths to the total needed for election without Ohio, the state’s 18 votes are considered crucial for Trump.

History says so, too: No Republican has won the White House without Ohio.

“Obama’s ability to win Ohio basically foreclosed any chance (John) McCain or (Mitt) Romney had,” said Kyle Kondik, of the University of Virginia Center for Politics, author of “The Bellwether: Why Ohio Picks the President.” “If Clinton wins Ohio, Trump has no chance.”

Kondik said, though, that Ohio has “a Republican lean” in presidential elections, but Trump still needs to pick up votes where Romney couldn’t in losing to Obama by more than 166,000 votes in 2012.

“Every presidential election, the dynamics of the race look a little different as far as where the pockets are where you feel there are new opportunities,” said Clinton’s Ohio campaign director, Chris Wyant, like his Trump counterpart Bob Paduchik, a veteran of multiple statewide campaigns in Ohio.

Wyant said she is doing better than Democrats in the past with “moderate” Republicans, and that Trump’s comments about women and “dangerous and divisive” positions have added to her support.

Trump’s campaign points to his shows of strength in blue-collar areas such as Youngstown and the Mahoning Valley, where he drew Democratic and independent support in the state’s March primary, and southern Appalachian Ohio.

Paduchik said the Trump campaign has a lot of enthusiasm among its volunteers in the state, and expects to run very well in exurban areas and traditional Democratic strongholds.

Polls also indicate Ohio, where early voting began last week, is one of only a handful of states that are tossups with less than a month to go.

“This race will likely come down to 100,000 votes in Ohio, probably 1.5-3.5 percentage points, and our campaign has the resources and enthusiasm we need to win for Mr. Trump,” Paduchik said.