This is the 16th in a weekly Fix series that focuses on the decennial redistricting process in key states. We call it “Mapping the Future”. The series aims to look forward to how the maps in these states could be drawn and what the best and worst outcomes for each party might be. Today we take on Michigan. (And make sure to check out the first 15 installments: Texas, Indiana, Georgia, Illinois, Massachusetts, Ohio, California, Nevada, Virginia, Pennsylvania, Florida, Utah, North Carolina ,Wisconsin and Maryland..)

Michigan has the unfortunate distinction of being the only state to actually lose population over the last decade, a shift that will cost it a House seat in 2012.

And given that Republicans control the redistricting process, Demcorats should watch their backs, right?

As it often is with redistricting, it might not be so simple.

Much like in other big states, Republican gains in Michigan in 2010 make it virtually impossible for the party to add winnable seats in 2012 without severely risking the districts they currently hold. That’s in spite of the fact that Republicans control all levers of the redistricting process in the Wolverine State.

In fact, the situation in Michigan is very much like the situation in another blue-tinting state we have looked at previously – Pennsylvania.

While the GOP controls 12 of 19 seats in Pennsylvania, it controls nine of 15 seats in Michigan. In both cases, many Republican-held districts went for President Obama in 2008 and will need to be shored up to ensure GOP incumbents have a chance to win them for the next decade.

And in both cases, the fact that the state is losing a seat means the map could be drawn any number of ways, with Republicans likely aiming to combine two incumbent Democrats into one district. In Michigan, that conversation has centered around two-term Rep. Gary Peters (D), a strong campaigner in a swing district in Oakland County, just north of Detroit.

The conventional wisdom has held that Peters’s 9th district would be combined with Rep. Sandy Levin ’s (D) strongly Democratic 12th district, which spans Oakland County and Macomb County to the east.

(Be sure to follow along on the congressional map here.)

The changes would then, theoretically, allow Republicans to shore up Rep. Thaddeus McCotter (R) in the 11th district west of Detroit by simply adding some of the more Republican parts of Peters’ district to it. (McCotter, though not seriously challenged in recent years, could be vulnerable to the right Democratic opponent; his district went 54 percent for Obama.)

And while that still seems possible, there are several complicating factors to that relatively easy redistricting solution.

First, the Census numbers released last week showed greater-than-expected population loss in Detroit. And in order to keep two majority-black, Detroit-based districts, as federal law requires, those seats will likely have to stretch up across the fabled 8 Mile Road and into Oakland and Macomb Counties — Peters’ and Levin’s territory — in order to pick up the necessary amount of African-American population.

Second, Michigan has in the past observed a rule that requires districts to cross as few city and county lines as possible. That would severely limit the creativity (to put it gently) that the GOP can use when drawing the map. At the same time, not all Republicans believe the guidelines are enforceable, and keep in mind: Republicans also took control of the state Supreme Court in November’s elections. So any court cases would be decided by the GOP.

Third, state Rep. Marty Knollenberg (R), the son of the incumbent congressman Peters ousted in 2008, is filing papers today to challenge Peters in 2012. That’s significant because Knollenberg sits on the state’s redistricting committee, which means he holds some sway over how the lines are drawn. Combining Peters and Levin together would, in all likelihood, make for a Democratic-leaning district that Knollenberg would have a tough time winning.

And fourth, most of the Republican incumbents in the state saw their districts go for Obama in 2008 and could be looking for help. And that focus could very well take precedence over eliminating Peters’ district.

“There is a lot less of a base on the Republican side and the Democratic side,” Republican redistricting expert Denise DeCook said of the Michigan voters. “They have gone to the almighty ticket-splitter side.”

Besides combining Peters and Levin, there are several alternatives for Republicans. Because the population loss is most severe in the Detroit area, though, the eliminated district will have to be in that part of the state.

One possibility would be to combine Peters and McCotter into the same district in hopes that McCotter could win head-to-head. Another would be combining Peters with Rep. Dale Kildee’s (D) Flint-based 5th district to the north.

About the only way that Peters isn’t part of the equation is if, somehow, Republicans target Kildee’s or longtime Rep. John Dingell’s (D) 15th district for elimination.

But that would be very tough.

Kildee’s 5th district covers the state’s major Democratic bastion outside of the Detroit area — Flint-based Genesee County — and nearby Republicans won’t want those voters. Even if he is to be combined into a district with Peters, Kildee’s old constituents would likely dominate the new district.

Dingell’s strongly Democratic southeastern district, meanwhile, is land-locked by the majority-black Detroit districts, McCotter’s district and vulnerable Rep. Tim Walberg’s (R) 7th district to the west.

Those majority-black districts may take in some of Dingell’s black voters, but they won’t be able to take on many of Dingell’s white voters, since they need to remain majority-black. And that means lots of Dingell’s white Democrats would likely have to by put in either McCotter’s or Walberg’s district – neither of which is a good option for the GOP.

If Republicans want to help McCotter and Walberg, then, Peters appears to be the easy answer.

Walberg’s district is another main concern for the GOP. He lost his seat in 2008, only to reclaim it in 2010, and he could really use some help. Unfortunately for him, there aren’t a lot of good options.

Walberg’s south-central 7th district is surrounded by Rep. Fred Upton’s (R) 6th district to the west, freshman Rep. Justin Amash’s (R) 3rd district and Rep. Mike Rogers’s (R) 8th district to the north, and McCotter and Dingell to the east. Of those districts, only Amash’s didn’t vote for Obama (Obama lost it by 2,000 votes). That means any help Walberg gets would make someone else’s reelection tougher.

Walberg could potentially swap some territory with Dingell, but finding strongly Republican areas in Dingell’s district is tough, and Michigan’s redistricting rules could make it impossible to cross county lines for a few precincts here and there.

“I don’t know if there’s any good way to help out Walberg,” said one Michigan Republican close to the process.

The third important area for the GOP is freshman Rep. Dan Benishek’s (R) 1st district, which spans the Upper Peninsula and the northern part of the Lower Peninsula. Long held by Democratic Rep. Bart Stupak, it leans slightly Republican but is hardly safe.

The most likely scenario appears to be Benishek giving up Democratic-leaning Bay County in the southeastern part of his district and grabbing Republican-leaning Grand Traverse County and its neighbors in the northwestern part of the Lower Peninsula.

Again, though, this is not ideal. That’s because whatever help Benishek gets likely comes at the expense of Rep. Dave Camp’s (R) 4th district, which – you guessed it – went for Obama in 2008. Michigan Republicans will do what they need to in order to protect the powerful House Ways and Means Committee chairman, and handing lots of his red territory to Benishek could be tough to stomach.

In fact, plenty of members with higher standing than freshmen like Walberg and Benishek could be looking for help too; only three of the state’s congressional districts went for Sen. John McCain (R-Ariz.) in 2008. If Camp and Upton – both chairmen – and Rogers, a serious player in the House GOP ranks, come looking for some help, it will be hard for Republicans to shore up the two freshmen and McCotter, and it could complicate efforts to combine two Democrats in an optimal way.

Yet again, there aren’t a lot of great options for Republicans, and drawing the map will be a very uncertain process.

“You’re squeezing a balloon here,” said redistricting expert Ed Sarpolus. “It’s got to give somewhere.”