Can You See Rob Portman Driving a Trump Win in Ohio?

According to The Wall Street Journal, the low-key, establishment GOP senator could do just that. In what Reid J. Epstein calls a “reverse coattails” process, Portman’s strong ground game in Ohio could give Trump the boost of Republicans showing up at the polls he needs to edge out Hillary Clinton in the Buckeye State.

If Donald Trump wins Ohio, it may be because of the groundwork laid byRob Portman, the state’s Republican senator who avoided the stage, the presidential nominee and the spotlight during the Republican Party’s Cleveland convention in July.

Mr. Trump’s campaign only recently started organizing voters here—months after Democratic rival Hillary Clinton—while Mr. Portman has for nearly two years been identifying and courting GOP voters in anticipation of a tough re-election race.

Consequently, Ohio may be a rare case study in reverse political coattails, with big stakes for Mr. Trump. Ohio has backed the presidential winners in the past 13 elections, and no Republican in modern history has won the White House without capturing Ohio.

In typical presidential years, the White House nominee drives party turnout for down-ticket candidates. Here, the Portman campaign, which began recruiting volunteers in high school government classes across the state in March 2015, is the primary point of contact for GOP voters.

“In Ohio, everyone is riding Rob Portman’s coattails,” said Donald Larson, a Republican who is challenging Democratic Rep. Marcy Kaptur.

It is an advantage that may help Mr. Trump steal a state from the Democratic column; polls show Mrs. Clinton and him in a dead heat. Meanwhile, Mr. Portman is leading his Democratic opponent, former Gov. Ted Strickland, by 13 percentage points, according to the Real Clear Politics average of public surveys.