Incumbents will be on defense and challengers in key House races will face their first tests in Tuesday’s primaries, as voters in seven states head to the polls. 

Five states are holding their regularly scheduled primaries, while Republicans in Mississippi and South Carolina will weigh in on House primary runoffs. Tuesday will also determine whether 2012 presidential nominee Mitt Romney and former Rep. Michael G. Grimm, a convicted felon, can jump-start their political comebacks. 

Watch: Can a Felon Make a Congressional Comeback? What to Watch in New York’s 11th District Primary

Here’s what to watch in each state:

New York

The Empire State is an important battleground for House Democrats, who are targeting nine Republican-held seats. The matchups appear set in at least two targeted upstate races. Democratic Assemblyman Anthony Brindisi is poised to take on freshman GOP Rep. Claudia Tenney in the 22nd District, while in the 27th, Grand Island Town Supervisor Nate McMurray is the only Democrat running against Republican incumbent Chris Collins, the first member of Congress to endorse Donald Trump in the 2016 presidential race.

But crowded fields and intraparty divisions dominate several contests.

The Republican primary has gotten more attention than the Democratic field in New York’s 11th District, based in Staten Island, where incumbent Dan Donovan faces his predecessor, Grimm. Trump backed Donovan late last month, and the strength of that endorsement will be put to the test Tuesday. Donald Trump Jr. and Trump lawyer and former New York City Mayor Rudy Giuliani both recorded robocalls for Donovan in the final days of the contest.

Some Republicans fear a Grimm victory could put the seat in play for Democrats. The Democratic Congressional Campaign Committee has taken sides in the party’s crowded primary, adding Army veteran Max Rose to its Red to Blue program for strong challengers.

The role of national Democrats in the primary for the Syracuse-anchored 24th District has sparked some local pushback. The DCCC recruited former Syracuse mayoral candidate Juanita Perez Williams to jump in the race to take on two-term GOP Rep. John Katko shortly before the filing deadline, even though local Democrats had coalesced around professor Dana Balter.

The DCCC has not weighed in on the crowded primary in the Hudson Valley-based 19th District, which could be one of the most competitive races in the country. Seven Democrats are vying to take on freshman GOP Rep. John J. Faso, five of them with sizable campaign war chests. Lawyer Antonio Delgado, Army veteran Pat Ryan and businessman Bryan Flynn have all spent more than $1 million so far. Gareth Rhodes, who worked for Democratic Gov. Andrew M. Cuomo, was endorsed by The New York Times last week. EMILY’s List has endorsed the only woman on the Democratic side, Erin Collier, although the pro-abortion rights group has not spent in the race.

Democrats are targeting four other New York Republicans: Reps. Lee Zeldin and Peter T. King in the Long Island-based 1st and 2nd districts, respectively; Rep. Elise Stefanik in the sprawling, rural 21st District; and Rep. Tom Reed in the 23rd District along the state’s Southern Tier. Inside Elections with Nathan L. Gonzales rates all four races Solid Republican.

A handful of safe Democratic districts are also hosting primaries, including the open-seat race to replace the late Democratic Rep. Louise M. Slaughter in the Rochester-based 25th District. New York State Assembly Majority Leader Joe Morelle is considered the front-runner, and Republicans plan to tie him to corruption in Albany.

In New York City, four longtime Democrats, including House Democratic Caucus Chairman Joseph Crowley, have been spending big to fend off primary challengers. Few Democratic incumbents have drawn formidable challenges nationwide this campaign cycle, and the lawmakers’ spending signal they are taking these challenges seriously.

Maryland

What does $11.5 million buy you? Potentially a Democratic nomination for Congress. But there’s no guarantee. Wine store magnate David Trone spent even more than that in bidding for the 8th District in 2016 and came up short. This year, his closest competition in the eight-way primary for the neighboring 6th District is state Del. Aruna Miller, who’d be the state’s best chance to elect a woman to Congress this year. (It’s the first time in more than 40 years that Maryland has no women in its congressional delegation.)

Miller has the backing of EMILY’s List, but the group hasn’t made any independent expenditures for her in the Solid Democratic race. Women have been winning Democratic primaries around the country this year, and Miller checks many of the boxes of 2018’s successful candidates — she’s an immigrant, has a science background and is a state legislator.

Utah

Romney would be well on his way to a political comeback if he win’s Tuesday’s GOP Senate primary in Utah against state Rep. Mike Kennedy, who narrowly bested him at the party convention in April. The former Massachusetts governor spent nearly four times as much as Kennedy in the pre-primary reporting period between April 2 and June 6 — $1.4 million to his opponent’s $388,000.

National Republicans expect Romney to win, and he would be highly favored in November against Salt Lake County Councilmember Jenny Wilson, who secured her party’s endorsement at its convention. Inside Elections rates the Senate race Solid Republican.

In the 3rd District, GOP Rep. John Curtis also faces a primary for a first full term, after winning a November special election to replace Republican Jason Chaffetz. Curtis will once again face former state Rep. Chris Herrod, whom he defeated in the special election primary last year.

Colorado

GOP Rep. Doug Lamborn is facing four primary challengers in the 5th District, anchored in Colorado Springs. He survived getting kicked off of the primary ballot due to a challenge to his petition signatures. Lamborn has fended off primary challenges in the past, and some party strategists believe he will prevail on Tuesday, pointing out that the multiple GOP candidates could split the anti-Lamborn vote.

Centennial State Democrats will be watching the open primary in the Boulder-based 2nd District to replace Rep. Jared Polis, who is seeking the Democratic nod for governor. Joe Neguse, a member of Colorado University’s Board of Regents, has spent nearly nine times more than the other Democrat in the race, Mark Williams, an Air Force veteran and a former Boulder County Democratic Party chairman. Neguse has been endorsed by former Vice President Joseph R. Biden Jr. 

Democrats will also be facing off in the 6th District in the Denver suburbs to take on GOP Rep. Mike Coffman, a so far elusive Democratic target. Army veteran Jason Crow, who has the backing of the DCCC and Democratic leadership, faces Levi Tilleman, a former Obama Energy Department official and the grandson of the late California Rep. Tom Lantos. 

Oklahoma

Republicans in the Tulsa-anchored 1st District are looking to replace former GOP Rep. Jim Bridenstine, who left in April to become NASA administrator. His seat will remain vacant until November, and the general election winner will serve out the rest of his term. Whoever wins Tuesday’s GOP primary will be the the favorite come fall. Trump won the 1st by 29 points and Inside Elections rates the race Solid Republican.

The conservative Club for Growth PAC has endorsed former military intelligence officer Andy Coleman, and its political arm has spent more than $345,000 on the race, mainly to oppose businessman Kevin Hern. One national strategist expected Hern to win, and Hern has spent more than $1 million on the race. (He loaned his campaign $700,000). Bridenstine has not endorsed a candidate, but he sharply criticized Hern for using his image in campaign ads. The Tulsa World reported that some of Bridenstine’s former campaign staffers are working for Coleman.

Runoffs

Mississippi

The Magnolia State missed its chance to elect its first woman to Congress earlier this month, when the three women running for the open 3rd District took the bottom three spots in the six-way primary. With no one clearing 50 percent, the top-two vote-getters advanced to Tuesday’s runoff. District Attorney Michael Guest finished with 45 percent, while Whit Hughes, the former chief development officer of Baptist Health Systems, finished with 22 percent, according to The Associated Press.

Guest already had the backing of outgoing GOP Rep. Gregg Harper, and he’s won the support of Republican Gov. Phil Bryant since the primary. Hughes, a former Mississippi State University basketball star, picked up the endorsement of the Tea Party Express over the weekend. This is a Solid Republican race, so Tuesday’s winner is almost certainly coming to Congress next year.

South Carolina

The Palmetto State also has a runoff for a Solid Republican race. None of the 13 candidates in the June 12 primary for the open 4th District received more than 50 percent of the vote. (Republican incumbent Trey Gowdy, chairman of the Oversight and Government Reform Committee, is not seeking re-election.) Former State Sen. Lee Bright finished first with 25 percent of the vote, ahead of state Sen. William Timmons with 19 percent.

The race has become yet another ideological proxy fight within the GOP. Club for Growth PAC has backed Bright, as have Reps. Thomas Massie of Kentucky and Steve King of Iowa and Texas Sen. Ted Cruz. Bright, who challenged Sen. Lindsey Graham in a 2014 primary, has said he’d like to join the Freedom Caucus, if elected. Club for Growth Action has spent more than $300,000 attacking the conservative credentials of Timmons, who has the support of Florida Sen. Marco Rubio. One pre-primary ad attacked Timmons for allegedly criticizing Trump. The nonprofit group Conservative Leadership Alliance has reportedly spent against Bright.