(CNN)Welcome to the first big primary night of the 2018 election!
Four states -- Indiana, Ohio, North Carolina and West Virginia -- will hold party primaries. There's a LOT to look at, so here's a handy, dandy viewer's guide for the most important storylines of the night.
1. Can Don Blankenship win? The West Virginia coal mine owner has used his own money to fund lots and lots of ads in his GOP primary race against Rep. Evan Jenkins and state Attorney General Patrick Morrisey. Of late, Blankenship has drawn lots of national attention -- all of it bad -- for his nativist and racist attacks on Transportation Secretary Elaine Chao and her husband, Mitch McConnell. If Blankenship wins, Democratic Sen. Joe Manchin will likely cruise to a second term.
2. Sen. Mike Braun? The former state representative used more than $5 million in personal money to dominate the airwaves in the Indiana Republican US Senate primary. His two opponents -- Reps. Luke Messer and Todd Rokita -- got bogged down fighting one another and their connection to Washington. If Braun wins, his personal wealth could save Republicans some cash that the party could dump into other races.
3. Can Dennis Kucinich show the power of the left? The former Ohio congressman -- and presidential candidate -- is challenging former Consumer Financial Protection Bureau Chair Richard Cordray for the Democratic nomination for governor. Kucinich has name ID and is a darling of liberals. Cordray is seen as the more electable of the two in the fall.
4. Is another Pence coming to Washington? In Indiana's 6th District, which Messer left to run for governor, Greg Pence, the vice president's older brother, is the favorite in the GOP primary. If Pence wins tonight, he'd be a heavy favorite to represent this eastern Indiana seat in Congress since President Trump carried it with 68% in 2016.
5. A Trump bump in Ohio? Trump convinced Rep. Jim Renacci to switch from the governor's race to the Senate race when favorite Josh Mandel dropped out of the race suddenly in January. ".@JimRenacci has worked so hard on Tax Reductions, Illegal Immigration, the Border and Crime," Trump tweeted last week. "I need Jim very badly to help our agenda and to keep MAKING AMERICA GREAT AGAIN! He will be a fantastic Senator for the Great State of Ohio, and has my full endorsement!" Renacci should win the GOP nomination. But does Trump's endorsement turn the primary into a Renacci rout?
The Point: The Senate races in Indiana and West Virginia -- and, to a lesser extent, Ohio -- have huge national implications for the fall. Ditto the Ohio gubernatorial primaries. Tonight will give us our first hints of how the two parties are reacting to the Trump era -- and what voters make of it too.