Supporters of President Donald Trump, wearing Mike Braun for Congress shirts, cheer during a campaign rally at the Ford Center in Evansville, Ind. AP

In this Aug. 31, 2018, photo, President Donald Trump holds up a list of his administrations accomplishments while speaking at a Republican fundraiser at the Carmel Country Club in in Charlotte, N.C. Heading into the midterms, 2018's most volatile candidate is not on the ballot. But Trump is still taking his freewheeling political stylings on the road on behalf of his fellow Republicans, preparing to ramp up his campaign schedule in a campaign sprint to Nov. 6 (AP Photo/Pablo Martinez Monsivais) Pablo Martinez Monsivais

Heading into the midterm elections, the most volatile candidate this year isn’t on the ballot.

But President Donald Trump still loves to take his freewheeling political stylings on the road on behalf of his fellow Republicans and he’s raring to go for the sprint to Nov. 6.

His eagerness to campaign for candidates – and protect his political flank – has led Republican officials and Trump’s political team to devise a strategy for managing the president’s time. It’s designed to keep him in places where he can be helpful.

They’re also determined to try to manage his unpredictability so the party’s strongest asset in turning out core GOP voters doesn’t end up doing damage instead.

There’s a constant effort to keep him on best behavior.

This past week, Trump heeded pleas from advisers and Colorado Sen. Cory Gardner, head of the GOP Senate campaign committee, to refrain from picking a favorite in the fractious Arizona primary, waiting until after the results were in to back the winner. Later, at a rally in Indiana for Senate candidate Mike Braun, the president largely stuck to his script, promoting his agenda and criticizing Sen. Joe Donnelly, D-Ind.

“Senate Republicans will not get to where they need to go without the president this fall. That means doing exactly what he’s been doing,” said Josh Holmes, a longtime adviser to Senate Majority Leader Mitch McConnell, R-Ky. “The great danger in a midterm is an enthusiasm gap and there is nobody who can close the enthusiasm gap quite like the president.”

Aides believe Trump’s drawing power is critical to a strong turnout among the most loyal GOP voters, which is helpful in many statewide contests. But his presence could be counterproductive in many House districts where incumbents are struggling to hold onto voters in the center.

But this is a celebrity-turned-president who hardly is a selfless leader of his adoptive party. He launched his own re-election campaign weeks after his swearing-in last year, rather than waiting until after the midterm elections, as did his predecessors. With Democrats increasingly optimistic about retaking the House, Trump is motivated by self-protection. He’s keenly aware of the threats and investigations that could come his way if Democratic hold a majority in either the House or Senate.

It hasn’t all been smooth sailing, and Trump created an unnecessary political firestorm with his delayed and muted response to the death of Sen. John McCain. Still, aides think he generally has grown more focused and disciplined entering the final push to the fall elections.

At his Indiana rally Thursday night, Trump stuck to familiar themes, talking about tax cuts and trade tariffs, slamming high-tech companies, railing against the Justice Department and calling MS-13 gang members animals. But he did not mention McCain, avoiding recounting the well-worn tale about the senator’s pivotal vote against the president’s health care bill.

After a week in which aides pushed Trump to rise above his personal grudges against McCain, the mere fact that Trump kept the senator out of his remarks was notable.

While Trump’s White House remains marked by turbulence, insiders said the political shop has managed to impose some discipline. On potential endorsements, for example, political director Bill Stepien and adviser John DeStefano bring Trump detailed binders on candidates’ voting records, including their past comments on Trump, where they have broken with the president and other details.