Tuesday night features some of the most intense — and final — tea party-vs.-business contests of the GOP primary season.  

Polls close in Michigan and Kansas at 9 p.m. EST. Washington State has a mail-in ballot system, with the first set of results expected to be released by 11:30 p.m. EST.  

Here are the six things to watch in those states:  

1. How does Sen. Pat Roberts’ tea party challenger fare? Sen. Pat Roberts, R-Kan., is favored to win the GOP Senate primary, where he faces Dr. Milton Wolf. There is tepid enthusiasm for Roberts, who is fighting an image as a creature of Washington. But Wolf never garnered much momentum, locally or nationally.  

Still, Wolf’s share of a vote will give some clues about the future of the Republican party in this state. GOP infighting has absorbed the gubernatorial race, the results of which could determine the party’s standing in the state for a while.  

2. In Michigan, what will happen to Rep. Justin Amash?
Business-friendly Republican groups have made no secret of their hope to oust Amash with their candidate, deep-pocketed Brian Ellis. But tea party aligned groups and members circled their wagons early around the sophomore Republican.  

Last week, the Club for Growth aired a last-minute television buy on Amash’s behalf in the 3rd District. It was either a sign Amash was in trouble, or that conservatives wanted to rack up his margin of victory in the wake of other losses this cycle.  

3. Is there a sliver of hope for Rep. Kerry Bentivolio, R-Mich.?  Probably not, according to retiring Rep. Mike Rogers, R-Mich.  

“This is the first real test of Mr. Bentivolio,” Rogers said during votes last week. “He was the accidental candidate, and I think this is the real test. And one thing you know about this place is you really need to be tested here.”  

Bentivolio’s primary rival is attorney David Trott, a candidate with a deep well of money to self-fund and political connections.  

Democrats have made some noise about playing for the seat in the fall, but for now the race is rated Favored Republican by the Rothenberg Political Report/Roll Call.  

4. Will name recognition carry former members over the finish line in comeback bids?  Two former members hope Tuesday translates to career comebacks: Todd Tiahrt, a Kansas Republican, and Hansen Clarke, a Michigan Democrat.  

But neither man is running a strongly organized or well-funded efforts. Tiahrt threw his lot in with moderates  in hopes they boost him over his GOP successor, Rep. Mike Pompeo.  

Clarke faces  Southfield Mayor Brenda Lawrence, an EMILY’s List endorsee, and state Rep. Rudy Hobbs, a protegee of Rep. Sander M. Levin, D-Mich. This is a race to replace Rep. Gary Peters, a Democrat running for Senate.  

If either Tiahrt or Clarke wins his primary on Tuesday, it will be thanks to their familiarity in voters. Both races are all-but-certain to determine the winners in the fall.  

5. Who replaces retiring Michigan Republican Reps. Dave Camp and Mike Rogers? Businessman Paul Mitchell is overwhelming state Rep. John Moolenaar in television advertising and direct mail in primary to replace Camp — thanks to Mitchell’s self-funding. Tuesday night will likely determine Camp’s successor.  

In the race to replace Rogers, former state Senate Majority Leader Mike Bishop and state Rep. Tom McMillin are battling over the GOP nod in Michigan’s 8th District. Democrats have telegraphed they would prefer to face McMillin in this slightly competitive race (rated Leans Republican ) for the party.  

6. Will Republicans avoid chaos in Washington State? Washington, like California, has a jungle primary where the top two candidates, regardless of party, proceed to the general election. There’s a crowded, 12-candidate field for retiring Republican Rep. Doc Hastings’s seat.   

Republicans are confident two of the candidates in their top tier — attorney George Cicotte, ex-NFL player Clint Didier, state Sen. Janéa Holmquist, former state Agriculture Director Dan Newhouse — will be on the ballot in the fall.  

But with such a large field, it’s possible — although unlikely — two Democrats muscle their way to the top of the heap and into the fall contest.  

Alexis Levinson contributed to this report.