On Thursday, a three-judge panel tossed Michigan's current boundaries for about three dozen congressional and state legislative seats, saying they were unconstitutionally gerrymandered to favor Republicans overall.

If it stands, the ruling will throw the 2020 election into a state of confusion, with new lines needing to be drawn and state Senate seats — not supposed to be up for election until two years later — being brought before voters early.

But there's a good chance that won't happen, at least not as quickly as one might believe from the ruling. Here's what you need to know:

What did the court rule?

A panel made up of three federal judges, one from the U.S. 6th Circuit Court of Appeals in Cincinnati and two others from Michigan, decided in favor of the League of Women Voters and several Democratic plaintiffs that 34 districts — nine congressional, 10 state Senate and 15 state House districts — were unconstitutionally gerrymandered and gave the state until Aug. 1 to draw up new lines for the 2020 election or the court would do it for them.

Why were the lines found to be unconstitutional?

In its 146-page opinion, the panel found that Republicans in charge of drawing and enacting the political lines after the 2010 Census did so in a way that put Democratic voters at such a disadvantage as to be unconstitutional. They did so, the panel found, by "packing" or "cracking" geographic blocs of Democratic voters, meaning they either packed them into one district or so diluted their numbers in others as to make their strength far less than it would otherwise be. The court found that violated the First Amendment right to association and 14th Amendment right to equal protection under the law.

What happens now?

The court gave the state Legislature until Aug. 1 to draw new lines for the 2020 election. But there is every indication that Republicans in the state Legislature will appeal the ruling to the U.S. Supreme Court — which can directly take redistricting cases. If that happens, they most likely will request a delay on the judges' ruling until the case can be heard and decided. The Supreme Court has granted those delays in similar cases. Complicating matters, however, is the fact that the Supreme Court — which now has a clear conservative majority — heard arguments this spring in similar cases from Maryland and North Carolina and is likely to rule on those before it ends its term in June or early July. Whatever gets decided in those cases could potentially set a precedent that effectively decides the Michigan case.

What if the Supreme Court doesn't delay or overturn the ruling?

The state Legislature — which is controlled by Republicans — has until Aug. 1 to draw new lines or the three-judge panel says that it will do it. Any legislative plan, by the way, would also have to be signed off on by Gov. Gretchen Whitmer, a Democrat. In the meantime, state Senate Majority Leader Mike Shirkey, R-Clarklake, said that the Legislature "will prepare to comply with this most recent ruling while we await the outcome of the appeal." He's not saying more than that, but one possible next step is the appointment of a committee of lawmakers to start working on drawing new maps.

Didn't a court force Pennsylvania to redraw its congressional boundaries?

Yes, last year. But that was a state court, not a federal one. In the recent gerrymander cases that have reached the U.S. Supreme Court, the court hasn't yet told a state it has to redraw its lines — though several of those cases are pending.

Didn't Michigan just pass a referendum on redistricting?

It did, last November. That creates an independent commission to draw political district lines in the future as a way to stop gerrymandering, which is the practice of drawing contorted, unnatural district lines as a way to favor or punish one political party or another. But that commission doesn't really get started until after the 2020 Census and its final product won't be in place until the 2022 election. And, yes, that means that the court's decision — if it goes into effect — would result in redrawn lines for the 2020 election and then wholly new lines for 2022.

Who's affected by the court decision?

It's impossible to tell. In one way, everyone in the state could be affected — and in a way already has been —- since the decision suggests that Republicans created an unfair political advantage that allowed them to wield more than their share of power in both Congress and the two chambers of the Michigan state Legislature. That calls into question all sorts of political acts that the court decision leaves in place. As to the future, redrawing those political lines in a way deemed fair by the court would likely involve changes not just to the 34 districts challenged in court but to those all over the state, as changing one district's lines almost inevitably means changing those around them in order to keep the number of people represented relatively constant.

Will Democrats be helped by the decision?

Presumably, yes, if it stands. But that doesn't necessarily mean that the Democrat in every district in the state automatically gets an advantage or that every district becomes politically competitive. There will still be many districts in areas that are predominantly Republican or predominantly Democrat that you would expect to remain so.

How will voters be impacted?

There is the possibility that the lines of the district any particular voter is in could change once for 2020 and again for 2022. And there is the chance that the district you end up in looks different — both geographically and politically — than the one you're currently in.

Which congressional districts are directly affected?

There are nine of them. Here's their number, general location and who is the current officeholder:

1st, Upper Peninsula and northern Michigan, U.S. Rep. Jack Bergman, R-Watersmeet.

4th, mid-Michigan, U.S. Rep. John Moolenaar, R-Midland.

5th, Flint, Saginaw, Bay City, U.S. Rep. Dan Kildee, D-Flint Township.

7th, south-central Michigan, U.S. Rep. Tim Walberg, R-Tipton.

8th, northwest Oakland, Livingston and Ingham counties, U.S. Rep. Elissa Slotkin, D-Holly.

9th, parts of Oakland and Macomb counties, U.S. Rep. Andy Levin, D-Bloomfield Township.

10th, parts of Macomb County and the Thumb, U.S. Rep. Paul Mitchell, R-Dryden.

11th, parts of Oakland and western Wayne counties, U.S. Rep. Haley Stevens, D-Rochester Hills.

12th, parts of Wayne and Washtenaw counties, downriver, U.S. Rep. Debbie Dingell, D-Dearborn.

Wait, aren't most of those seats held by Democrats already?

Yep, five of the nine. But that's only since the 2018 election, before which two of those seats — the 8th and the 11th — were considered reliably Republican. Still, the fact that Democrats were able to beat the odds to win some of these seats — or hold others in which Democratic voters are packed in such a way as to dilute their strengths in other districts — doesn't diminish the argument for drawing fair boundary lines.

What about the state Senate?

This gets really complicated because there isn't even supposed to be an election for some state Senate seats in 2020. But the panel said there needs to be an election in the affected districts because of the gerrymandered lines. That, in turn, raises questions about whether current state senators in second terms supposed to last through 2022 can run again because of term limits. That applies to three of them: Sens. Jim Ananich, Ken Horn and Jim Stamas. Again, though, it all depends on whether the decision goes into effect or not.

At present, of the 10 directly affected seats, six are held by Republicans and four by Democrats. Here are their district numbers and and who they are. All state Senate terms are for four years.

8th, Sen. Peter Lucido, R-Shelby Township.

10th, Sen. Michael MacDonald, R-Macomb Township.

11th, Sen. Jeremy Moss, D-Southfield.

12th, Sen. Rosemary Bayer, D-Beverly Hills.

14th, Sen. Ruth Johnson, R-Holly.

18th, Sen. Jeff Irwin, D-Ann Arbor.

22nd, Sen. Lana Theis, R-Brighton.

27th, Sen. Jim Ananich, D-Flint.

32nd, Sen. Ken Horn, R-Frankenmuth.

36th, Sen. Jim Stamas, R-Midland.

What about the state House seats?

Of the 15 districts directly affected, seven are currently held by Republicans and eight by Democrats. Because of term limits — which limit a state representatives to no more than three terms — three current legislators wouldn't be able to run again, state Reps. Rebekah Warren, Jon Hoadley and Vanessa Guerra.

Here are the affected districts by number and current representative:

24th, Rep. Steve Marino, R-Harrison Township.

32nd, Rep. Pamela Hornberger, R-Chesterfield Township.

51st: Rep. Mike Mueller, R-Linden.

52nd, Rep. Donna Lasinski, D-Scio Township.

55th: Rep. Rebekah Warren, D-Ann Arbor.

60th, Rep. Jon Hoadley, D-Kalamazoo.

62nd, Rep. Jim Haadsma, D-Battle Creek.

63rd, Rep. Matt Hall, R-Emmett Township.

75th, Rep. David LaGrand, D-Grand Rapids.

76th, Rep. Rachel Hood, D-Grand Rapids.

83rd, Rep. Shane Hernandez, R-Port Huron.

91st, Rep. Greg VanWoerkom, R-Norton Shores.

92nd, Rep. Terry Sabo, D-Muskegon.

94th, Rep. Rodney Wakeman, R-Saginaw Township.

95th, Rep. Vanessa Guerra, D-Saginaw.

How did elected officials react?

Those who did react, reacted about as you'd expect. U.S. Reps. Dan Kildee and Andy Levin, two Democrats, both said "Voters should choose their elected officials, not the other way around." Beyond promising an appeal, Republicans denounced the decision, with U.S. Rep. Bill Huizenga, R-Zeeland, whose district wasn't even part of the lawsuit, saying, "Judges and courts should not be in the business of drawing legislative boundaries." What's perhaps more surprising is how little public reaction to the decision has come from officeholders in both parties, however. That may be an indication that, without anyone knowing whether this decision will stand and, if it does, what the new lines will look like, that elected officials are taking a wait-and-see approach.

Read more:

The Supreme Court takes on gerrymandering. A cottage industry wants to prove it's gone too far

Michigan's anti-gerrymandering proposal is approved. Now what?

Contact Todd Spangler:tspangler@freepress.com. Follow him on Twitter@tsspangler. Read more onMichigan politics and sign up for ourelections newsletter. Staff writer Kathleen Gray contributed to this report.