The bench is deep there for the GOP and is weak for the dems. It's even thinner with Carl Marlinga's recent legal troubles(Macomb prosecutor). The only strong candidate the dems have is John Espinoza who is a state rep from a 58% Bush district(Port Huron City and Sanillac County). He won because he's an veteran, aggie and a nice guy who ran against a bigtime jerk for an open seat(where the GOP'er won by 9000 votes in 02). Espinoza will have a very tough race if he runs for re-election or if he runs for congress. The only other elected official democrats from that district are possible city county or county comissioner types which are stronger in smaller districts.
The GOP has some strong possible candidates here. In the state senate, there is Alan Sanborn(Macomb) and Jud Gilbert(St Clair). In the state house - Any of the Roccas(IF they are in the district as Sterling Heights was split between Miller and Sander Levin's seat), Jack Brandenberg (Macomb), Dan Acciavatti(Macomb), Brian Palmer(Macomb), Phil Pavlov(St Clair), John Stahl(Lapeer), and Tom Meyer(Huron) are all current state reps in this district. Steve Ehardt(who had Espinoza's seat) is a termed out state rep from the thumb as well. All of them are Republican and conservative.
If Miller runs, I think any of them could run, but I suspect at least one Thumb rep and one Macomber to run in a regionally based primary. The thumb is very conservative, but also very independent with it's own regional politics(like the UP and North Michigan to some degree)
One possible wildcard - David Bonior represented much of this district until 02. Bonior had Eastern Macomb and St Clair Counties. I can see Bonior possibly move from MtClemens next door to this district to take another shot at Congress. He's far left, but he's also a populist, and populists do very well in this district. Bonior's district ticketsplitted and went for Both Bushes twice, and Reagan twice. He is not to be taken lightly if he runs.
Wait, I was just reading this whole post: Did we beat Bonier in '02, or did he retire? I thought he was still in congress. I would have thought I would hear if he were beaten.
Either way, nice to know he's not around any more. Few members of congress were more dispicable.