Republicans don't know if they'll lose big or small on Tuesday, but they're already bracing for an epic blame game.

Why it matters: Privately, Republicans acknowledge it's not a complicated version of Clue. The leading suspect: Mr. President, in the Oval Office, with an assortment of weapons — and one war.

  • Returning Republican senators are unlikely to blame President Trump publicly. There's a price for that. And don't expect Trump to shoulder the responsibility.
  • But do expect departing GOP lawmakers to take shots at Trump or his team, and Trump to fire back at Senate Republicans, whom he's never been shy about torching.

The irony of Trump's second midterm: With Republicans privately resigned to losing the House, Trump can still credibly claim victory if they hold the Senate.

  • "It's Donald Trump's midterms. He gets all the credit if we win. He gets all the credit if we lose," one national GOP strategist told Axios.

The Iran war: From Alaska to Maine, Trump's decision to go to war with Iran — and the resulting spike in gas and diesel prices — has become a major political liability for Republican Senate nominees.

  • "It's not tariffs … it's the war, it's gas prices, it's diesel," Texas Attorney General Ken Paxton said at a closed-door fundraiser in September, Axios reported last month.

Tariffs: Trump's trade policies have compounded Republicans' affordability problems, particularly in farm country, where producers have faced higher costs and uncertainty over export markets.

  • "We need to end this tariff war now," former Rep. Mike Rogers (R-Mich.), the GOP Senate nominee, said in an October campaign ad, breaking with Trump over his tariffs on Canada.

Bad candidates: Trump's preferred nominees are also drawing blame, GOP strategists tell Axios.

  • Paxton in Texas and Sen. Darline Graham in South Carolina have forced Republicans to spend heavily defending races that should have been easier — and where the party had other options.

Complacent incumbents: Sens. Roger Marshall (R-Kan.) and Cindy Hyde-Smith (R-Miss.) are facing accusations of "arrogance" and "laziness" from Republicans frustrated that their once-safe seats have become late-breaking battlegrounds — exactly the complacency NRSC Chair Tim Scott warned against.

Weak governors: Underperforming gubernatorial nominees in Iowa, Michigan and Ohio threaten to drag down Republican Senate candidates. Vivek Ramaswamy, for example, saw his polling crater in the final weeks.

Recruitment failures: Republicans couldn't persuade Georgia Gov. Brian Kemp to run for Senate, and in New Hampshire settled for their second-choice Sununu — former Sen. John Sununu — instead of his brother, former Gov. Chris Sununu.

  • Meanwhile, Senate Minority Leader Chuck Schumer (D-N.Y.) landed marquee candidates in Alaska, Ohio and Iowa — though Michigan and Maine proved more difficult.

MAGA money: Trump's political operation amassed an enormous war chest, but some Republicans complain the money arrived too late to rescue vulnerable candidates.

Distractions: Trump's focus on D.C. construction projects, the Kennedy Center, Sen. Jon Husted's (R-Ohio) backside and the SAVE Act has frustrated Republicans desperate for a closing message focused on the economy.

  • "Reflecting Pool presser was an interesting choice for closing message," another national GOP strategist said of Trump's Monday news conference.