All 38 seats in the Michigan Senate are up for election in 2014. Republicans currently have a 26-12 supermajority, and have controlled the senate since 1983.
Republican control of the state senate has prevented democrats from complete control of Michigan’s government, and stopped a lot of bad things from being passed. More recently, the Republican supermajority has prevented some of Governor Snyder’s more liberal plans from being implemented.
Fortunately for Republicans, the Michigan state senate is up only in midterms, which favor Republicans much more than presidential years. 2010 was very good to the Michigan GOP. Republicans picked up four state senate seats (and one earlier in a 2009 special election).
Republicans had complete control of redistricting this cycle. They crafted a very effective map. One democrat district was eliminated in Wayne County and replaced by a Republican one in west Michigan. Four other dem districts were made more dem. Most of the potentially vulnerable Republican seats were made more Republican, though a couple got slightly worse due to the need to avoid splitting counties. The new map is actually cleaner than the old one, excluding the Detroit districts, which are ugly for VRA reasons.
There are ten open seats. Seven senators, four republicans and three democrats, are term-limited. Two republicans are just retiring, and one is running for Congress. Three Republican-held open seats (17, 20, 32) are tossups, and one other (13) could be competitive. Democrats have only one top challenger to a Republican incumbent (7), though another (34) could be competitive. Notably, dems failed to recruit credible candidates in several districts that were hotly contested in 2010 (29, 31, 38).
All but one of the current state senators are former state representatives. This pattern held in the past, and most credible candidates this time are current or former state reps.