Since President Donald Trump’s inauguration, an explosion of new Democratic candidates are stepping up to run for office at just about every level of government — and as the party heads into the 2018 election cycle, they’ve managed to secure a major head start in candidate recruitment.

In all but 15 districts, at least one Democrat has filed to run with the Federal Elections Commission. Of those 15 open seats, three have new candidates who have formally declared their candidacy but have not yet filed with the FEC.

That leaves just 12 congressional districts where Republicans do not yet have a declared challenger from the major opposition party. In one of those districts — Kentucky’s 5th congressional district — the filing deadline has already passed. But in the other 11 districts there is still time to file, with filing deadlines as far out as July.

For context, there are around 80 U.S. districts in which no Republican has filed to run. On Election Day in 2016, Democrats didn’t have a candidate in 28 congressional races, while Republicans had no candidate in 25 races.

Some Democratic political strategists, including former Democratic National Committee chair Howard Dean, have been arguing for years that Democrats should run a candidate in every race, even when the odds are considerably against them.

And with the December election of Doug Jones in Alabama, the party may inch closer to that position. If the Democrats can field candidates for the last crop of 11 seats before each state’s filing deadline, they could make the rare move of running a candidate in nearly every single House race in 2018.

Here are the districts that still don’t have a declared Democratic candidate, and the Republicans who hold currently hold those seats.

Utah’s 1st Congressional District

Chairman of the House Committee on Natural Resources Rob Bishop (R-Utah) Tasos Katopodis/Getty Images

Where’s that? The district includes Box Elder, Cache, Daggett, Duchesne, Morgan, Rich, Summit, Uintah, and Weber counties, as well as a part of Davis County.

Who’s there now? Rep. Rob Bishop (R-Utah)

What should I know about him? Bishop, who is chairman of the House Natural Resources Committee, went against popular opinion in his home state and supported Trump’s decision to shrink national monuments there. In fact, even before Trump made the decision, Bishop was a leading proponent of curtailing protections for federal monuments.

When is the filing deadline? March 15, 2018.

North Carolina’s 3rd Congressional District

Rep. Walter Jones, R-N.C. Andrew Harnik/AP

Where’s that? The district is on the northeastern shore of the state including Camden, Carteret, Currituck, Dare, Hyde, Jones, Onslow, Pamlico, and Tyrrell counties.

Who’s there now? Rep. Walter Jones (R-N.C.)

What should I know about him? Jones’s heterodox libertarian beliefs has made him an outsider in his own party. After help to lead the charge to rename french fries “freedom fries” during the Iraq war, Jones later reversed his position and became an outspoken critic of U.S. military intervention. Over the past two cycles he’s faced well-financed primary challenges from establishment Republicans, and likely will again.

When is the filing deadline? February 28, 2018.

Wyoming’s At-Large Congressional District

Rep. Liz Cheney (R-Wyo.) Matt Rourke/AP

Where’s that?: Literally all of Wyoming.

Who’s there now? Rep. Liz Cheney (R-Wyo.)

What should I know about her? She’s Dick Cheney’s daughter and political protégé.

That Dick Cheney? Yes, former Vice President Dick Cheney. She also famously severed her relationship with her gay sister in order to mount a failed Senate primary campaign in 2013 and 2014.

When is the filing deadline? June 1, 2018.

Kentucky’s 5th Congressional District (deadline passed)

Rep. Hal Rogers (R-Ky.) Chip Somodevilla/Getty Images

Where’s that? The district extends over a broad swath of Kentucky that includes Bell, Breathitt, Carter, Clay, Elliott, Floyd, Harlan, Jackson, Johnson, Knott, Knox, Laurel, Lawrence, Lee, Leslie, Letcher, Lincoln, Magoffin, Martin, McCreary, Morgan, Owsley, Perry, Pike, Pulaski, Rockcastle, Rowan, Wayne, and Whitley counties.

Who’s there now? Rep. Hal Rogers (R-Ky.)

What should I know about him? He was once named one of Congress’ “most corrupt members” by the watchdog group Citizens for Responsibility and Ethics in Washington. According to McClatchy, he’s also seen a significant decrease in fundraising power in recent months.

When is the filing deadline? Jan. 30, 2018. (Passed)

Kansas’ 1st Congressional District

House Speaker Paul Ryan of Wisconsin administers the House oath of office to Rep. Roger Marshall (R-Kan). Zach Gibson/AP

Where’s that? The district encompasses most of Kansas’ rural western and central region.

Who’s there now? Rep. Roger Marshall (R-Kan.)

What should I know about him? Marshall unseated incumbent conservative firebrand Rep. Tim Huelskamp in the 2016 Republican primary. Now, Huelskamp is running to try and reclaim his seat in 2018 — meaning the race will likely be fraught with GOP infighting.

When is the filing deadline? June 1, 2018.

Louisiana’s 1st Congressional District

House Majority Whip Steve Scalise (R-La.) Zach Gibson/Getty Images

Where’s that? The district is in southeastern Louisiana and includes Plaquemines, St. Bernard, and St. Tammany parishes, as well as parts of Jefferson, Lafourche, Orleans, Tangipahoa, and Terrebonne parishes.

Who’s there now? Rep. Steve Scalise (R-La.)

What should I know about him? Scalise is the House majority whip, making him the third highest ranking Republican in the House. He was severely wounded in the congressional baseball shooting in June.

But Scalise is also known for his ties to white supremacist groups in Louisiana, dating back long before Donald Trump was president and anyone had ever heard the phrase “alt-right.”

When is the filing deadline? July 20, 2018.

Louisiana’s 4th Congressional District

Rep. Mike Johnson (R-La.) Mike Johnson Facebook

Where’s that? The district makes up the northwestern corner of Louisiana including Allen, Beauregard, Bienville, Bossier, Caddo, Claiborne, De Soto, Evangeline, Natchitoches, Red River, Sabine, Union, Vernon, and Webster parishes and parts of St. Landry Parish.

Who’s there now? Rep. Mike Johnson (R-La.)

What should I know about him? Other than his youthful looks? Not much. Johnson just won his office in 2016, and doesn’t have a lot to show for his short time in office in his home district.

When is the filing deadline? July 20, 2018.

Louisiana’s 5th Congressional District

House Speaker Paul Ryan of Wis. administers the House oath of office to Rep. Ralph Abraham, R-La. Zach Gibson/AP

Where’s that? The district encompasses northeastern Louisiana, including Avoyelles, Caldwell, Catahoula, Concordia, East Carroll, Franklin, Grant, Jackson, La Salle, Lincoln, Madison, Morehouse, Ouachita, Rapides, Richland, Tensas, Washington, West Carroll, West Feliciana, and Winn parishes, as well as parts of East Feliciana, St. Helena, St. Landry and Tangipahoa parishes.

Who’s there now? Rep. Ralph Abraham (R-La.)

What should I know about him? Abraham is rumored to be considering a run for governor in the state’s 2019 election, and plans to make the decision this spring. Should he step down to seek higher office, the race will be for an open seat.

When is the filing deadline? July 20, 2018.

Mississippi’s 3rd Congressional District

U.S. Rep. Gregg Harper (R-Miss). Rogelio V. Solis/AP

Where’s that? The district cuts diagonally across the middle of the state includes Adams, Amite, Covington, Franklin, Jasper, Jefferson Davis, Kemper, Lauderdale, Lawrence, Lincoln, Neshoba, Newton, Noxubee, Pike, Rankin, Scott, Simpson, Smith, Walthall, and Wilkinson counties.

Who’s there now? Rep. Gregg Harper (R-Miss.)

What should I know about him? Harper is on a short list of officials who could potentially be appointed by the state’s governor to replace Sen. Thad Cochran, whose health has recently been diminishing. That could mean an open race in 2018.

When is the filing deadline? March 1, 2018.

Oklahoma’s 1st Congressional District

Rep. Jim Bridenstine (R-Okla.) Sue Ogrocki/AP

Where’s that? The district encompasses the area in and around Tulsa to the north and west of the city.

Who’s there now? Rep. Jim Bridenstine (R-Okla.)

What should I know about him? Bridenstine is Trump’s nominee to run NASA, and his confirmation is currently pending in the Senate. However, a history of climate change denial could derail his nomination to head one of America’s most important scientific agencies. Should he be confirmed, any Democratic challenger would be running for an open seat.

When is the filing deadline? April 13, 2018.

Oklahoma’s 3rd Congressional District

Rep. Frank Lucas (R-Okla.) Sue Ogrocki/AP

Where’s that? The district encompasses a large swath of the western part of the state, including the entire panhandle.

Who’s there now? Rep. Frank Lucas (R-Okla.)

What should I know about him? A staunch conservative, Lucas has faced backlash from some of his constituents for not being supportive enough of Trump. With the announced retirement of House Science Committee Chair Rep. Lamar Smith (R-Texas), Lucas would be next in line to lead the committee. Lucas is a longtime EPA critic.

When is the filing deadline? April 13, 2018.

Tennessee’s 6th Congressional District

U.S. Rep. Diane Black, a Republican candidate for Tennessee governor. Erik Schelzig/AP

Where’s that? The district covers north central Tennessee including Cannon, Clay, Coffee, Cumberland, DeKalb, Fentress, Jackson, Macon, Overton, Pickett, Putnam, Robertson, Smith, Sumner, Trousdale, White, and Wilson counties.

Who’s there now? Rep. Diane Black (R-Tenn.)

What should I know about her? She is leaving Congress to run for governor of Tennessee, so the race will be to fill an open seat in Congress.

When is the filing deadline? April 5, 2018.

Jan. 31, 2018, 4:54 p.m.: This article has been updated and will continue to be updated as new Democratic candidates enter the remaining races.