The first in a series on the risks and rewards of garnering party leaders' campaign trail support

As with real estate, the value of a Donald Trump endorsement tends to hinge on three things: location, location, location.

Put more bluntly, the president’s gusto for campaigning and his pledge to be more involved in the midterm elections could be either the Midas touch or the kiss of death for Republican candidates, depending on the state or district.

As primary season winds down and the general election ramps up, GOP campaigns and strategists are assessing the rewards and the risks of support from a campaigner-in-chief who is so beloved by the party base yet so polarizing outside of it.

In an election cycle that figures to be particularly colored by the occupant of the Oval Office, some Republicans in competitive districts are being forced to walk a tight rope between now and Nov. 6, while others are eager to have Trump boost their credibility among his supporters.

The notion that the president will be welcomed by some candidates in his party and shunned by others isn’t unique to Trump; vulnerable Democratic candidates in the last midterm tried to distance themselves from President Obama, for example. But GOP operatives note they must contend with a party leader who is far more unpredictable, and more drawn to controversy on the stump, than his predecessors. And his sustained dominance in the daily news cycle makes it difficult for candidates to distance themselves or create their own brands even if Trump isn’t dispatched to their districts.

“It's not like Trump is a precision bomb; he's like an earthquake,” says Virginia-based Republican strategist Tucker Martin. “The impact extends far beyond the epicenter. You can’t contain the impact of Trump.”

"It's not like Trump is a precision bomb; he's like an earthquake. The impact extends far beyond the epicenter." Tucker Martin, Republican strategist

Two cases freshly underscored the dynamic for the GOP heading into the fall campaigns: The night before Trump was scheduled to campaign for Republican Troy Balderson in Ohio’s 12th Congressional District special election, the president took a swipe at NBA star -- and Buckeye State favorite son -- LeBron James. The fact that the race in a deep-red, suburban district became a close one is itself indicative of the political climate in the Trump era. But Republicans reasoned that the animus toward Trump in OH-12, and elsewhere, is already baked in and that if GOP candidates are going to be tied to the president anyway, they might as well squeeze some political capital out of him while they can.

That risky bet appeared to pay off Tuesday night. Though the race is too close to officially call, Balderson leads Democrat Danny O’Connor by fewer than 2,000 votes, prompting Republicans to claim victory. One party operative familiar with congressional campaigns told RCP that Trump was “the difference maker,” and Republican National Committee Chairwoman Ronna McDaniel called the president “the best person to energize our voters.”

Trump was quick to claim credit. “When I decided to go to Ohio for Troy Balderson, he was down in early voting 64 to 36,” he tweeted. “That was not good. After my speech on Saturday night, there was a big turn for the better.”

Balderson thanked Trump and Vice President Mike Pence for their support. But in an election night statement he also acknowledged Ohio Gov. John Kasich, whose endorsement was designed to give the Republican candidate credibility with independent voters and GOP voters who had soured on Trump. That combination could be critical for Republicans in districts like these.

And in Kansas, Trump’s endorsement of gubernatorial candidate Kris Kobach over Republican incumbent Jeff Colyer threw the entire race on its head. With 95 percent of precincts reporting, the challenger leads by fewer than 600 votes. Kobach, the current secretary of state in Kansas and the vice chairman of the president’s now-defunct voter fraud commission, is a controversial figure. Republicans are concerned the party could lose the governorship with him atop the ticket in November. But he has been a loyal and longtime supporter of Trump’s, and the president ignored the advice of GOP officials who warned him of Kobach’s vulnerabilities.

“The president makes calculations based on different variables than we do,” said one GOP campaign operative. “We work with the variables on who is the best candidate to win, but the president and the White House might be working on different variables, where they value loyalty.”

Indeed, Trump has shown considerable deference to candidates who have been his steadfast defenders, even if doing so puts the party’s prospects in jeopardy. In the Florida gubernatorial race, for example, he endorsed Rep. Ron DeSantis, who had been considered a weaker general election candidate than Adam Putnam. But polls show that after receiving the president’s backing, DeSantis is now the frontrunner for the nomination.

Trump has also used endorsements to punish candidates for their disloyalty. In South Carolina’s 1st Congressional District primary, for example, he backed challenger Kate Arrington over Trump-critic and incumbent Mark Sanford -- who lost.

But in other cases, Trump has honored the wishes of party officials, even extending endorsements to former rivals or critics. He endorsed California Republican gubernatorial candidate John Cox, who didn’t support the president in 2016. Trump has also backed Texas Sen. Ted Cruz’s re-election bid and Utah U.S. Senate candidate Mitt Romney, even after both men opposed him during the 2016 campaign. In New York’s 11th Congressional District primary, he endorsed incumbent Rep. Dan Donovan over former Rep. Michael Grimm, who campaigned as an ally of Trump. In his endorsement, the president claimed that Donovan supported the GOP tax bill, though in fact the congressman opposed it.

And in a party runoff for Alabama’s 2nd Congressional District, he ultimately endorsed Rep. Martha Roby, who had rescinded her backing of Trump after the “Access Hollywood” tape surfaced in 2016. And he was quick to take credit for her success. “My endorsement came appropriately late, but when it came the ‘flood gates’ opened and you had the kind of landslide victory that you deserve. Enjoy!” he tweeted.

“It may not be as helpful in the general election, but right now in a Republican primary, Trump’s touch is the golden touch,” says former Rep. Tom Davis, who chaired the National Republican Congressional Committee.

"It may not be as helpful in the general election, but right now in a Republican primary, Trump’s touch is the golden touch.” Former Rep. Tom Davis

Elsewhere, and to the delight of GOP officials, Trump has been active in key Senate races in red states where Republicans hope to defeat Democratic incumbents and challengers. In Ohio, which Trump won by eight percentage points in 2016, Jim Renacci’s camp sees little downside in having the president campaign for the Republican against Democratic Sen. Sherrod Brown.

“Why not use the president every opportunity we get to help raise money and put a gigantic megaphone in front of Jim and help remind Trumps voters, especially those who voted for Brown in 2012, that the president supports Renacci?” said campaign communications director Leslie Shedd. “The congressman was an early endorser and a surrogate [for Trump]. He is Trump's guy here in Ohio.”

In the race for the open U.S. Senate seat in Tennessee, GOP Rep. Marsha Blackburn released an ad Tuesday touting her endorsement from Trump. The spot features footage of Blackburn embracing the president during a rally he held for her earlier this year. “Tennessee needs a senator who is going to support President Donald Trump,” said Blackburn, who is running against Democratic former Gov. Phil Bredesen.

But in many House races across the country, particularly those in swing or battleground districts, Trump could serve as an albatross for GOP candidates — even if he doesn’t campaign for or endorse them.

Davis, the former NRCC chair, says Republicans running for Congress this year face three main challenges when it comes to the president. First, Trump has juiced up the Democratic base. Second, there is a big question mark as to whether Trump voters will show up in November if the president is not on the ballot. And third, Independents tend to use the midterms as a check on the president, no matter the party.

“Trump helps you with getting our vote out, but you also worry about swing voters,” Davis says. “They like to put a check on him. They think he's erratic enough and want to have some guard rails.”

Bottom line, strategists say: The extent of Trump’s influence just depends on where you are. If you’re a candidate like New Jersey Rep. Leonard Lance or Virginia Rep. Barbara Comstock -- Republicans who represent districts Hillary Clinton won -- “you’re probably holding your breath” when it comes to Trump, Davis says. But if you’re a candidate in West Virginia or North Dakota or Indiana, “you’re going to clutch on tight.”

Caitlin Huey-Burns is a national political reporter for RealClearPolitics. She can be reached at chueyburns@realclearpolitics.com. Follow her on Twitter @CHueyBurns.