Republican Senate candidate John James reacts to learning he and his wife, Elizabeth, are expecting a boy at a primary night election party in Detroit on Aug. 7. (Paul Sancya/AP)

So far, the most furious congressional rivalry of the 2020 election cycle might not be between two candidates but instead between two Republican campaign committees.

The top GOP groups charged with respectively electing members of the Senate and the House are locked in a derby to woo John James, the 37-year-old Michigan businessman who mounted a surprisingly strong 2018 challenge to Democratic Sen. Debbie Stabenow and is pondering his next political move.

Will he mount another Senate run in 2020, challenging Democrat Gary Peters and delighting the National Republican Senatorial Committee? Or will he instead launch a House race against freshman Rep. Haley Stevens in the Detroit suburbs, pleasing the National Republican Congressional Committee?

The latest move to convince James — and the one man who could play an outsize role in his decision, President Trump — comes from the NRSC. In a memo obtained by The Washington Post, the group lays out the case that a statewide run by James could actually help Trump get elected by getting Republican voters in Detroit and its suburbs to the polls in a crucial swing state.

The memo appears to seek to quiet doubts about a second Senate run for James, including whispers — aired in a Politico story this week — that James running statewide could actually imperil Trump by driving up Democratic spending in the state.

“The president and John James can be like thunder and lightning,” an NRSC official said. “The president blows out northern Michigan by an unprecedented margin — he crushes it. And John James, his bread and butter is the south.” With the tag team, the official said, “they help each other. It presents itself plain as day in the numbers.”

The memo contains no methodological information on the polling, but it asserts that James is “in a statistical dead heat” with Peters, who is not especially well-known among Michigan voters. The memo notes that James performs unusually well for a Republican in Wayne County, where Detroit is located, cutting into the heavy Democratic advantage there, and enjoys a 27-point net favorable impression among voters in the suburban collar counties. Meanwhile, voters in those counties are evenly split on Trump, while Peters enjoys only a three-point net positive favorability.

The document also notes that James outperformed 2018 GOP gubernatorial nominee Bill Schuette by nearly 80,000 votes, making the Senate race three points tighter than the race for governor. It also notes that James won nearly 650,000 more votes last year than Peters’s last Republican opponent, Terry Lynn Land, won in 2014.

Still, recent public polls show Trump trailing several possible Democratic nominees, and there is the distinct possibility that, come November 2020, Trump’s unpopularity creates head winds James might not be able to overcome. But Republicans, according to the NRSC official, are urging James to look at the 2016 results, where GOP Senate candidates outperformed Trump in each of the eight most competitive battleground states with both offices on the ballot.

Whether this will sway James is unclear. He did not reply to messages left Tuesday at his business, Renaissance Global Logistics.

But in recent months James has consulted with both Sen. Todd C. Young (R-Ind.), the NRSC chairman, and Rep. Tom Emmer (R-Minn.), the NRCC chairman — as well as Trump himself, according to Republican officials. He is reportedly also under consideration as a possible Trump nominee to be United Nations ambassador, filling the vacancy created by Nikki Haley’s departure last year.

The NRSC and other Republican strategists view James as their clear top recruit in Michigan, one of only a small handful of states where the party has a credible opportunity to oust a sitting Democrat.

House recruiters, meanwhile, are counting on James paying attention to a different set of numbers: A recent internal Republican poll shows James beating Stevens, according to a GOP official. But there’s a catch: With Michigan’s congressional lines in flux thanks to a recent federal court ruling, it’s unclear just what electorate he might face in a 2020 House race.

“He’s a great talent, and wherever he runs, he will be an asset for Republicans,” said NRCC spokesman Chris Pack.