...Michigan- 52% of voters think Romney should release 12 years of his tax returns to 42% who think he should not. Among independents the breakdown is 59/36.

http://www.publicpolicypolling.com/main/2012/09/obama-up-7-in-michigan.html

PPP's first likely voters poll in Michigan this year finds Barack Obama with a solid lead in the state, 51-44. That's down a good bit from our last registered voters poll in July which found Obama ahead 53-39. That's a reflection of the fact that the state could be looking at a very different electorate in 2012 than it had in 2008. We find that 34% of likely voters on this poll are Republicans compared to 33% who are Democrats. Exit polls last time showed 41% of voters as Democrats and just 29% as Republicans.

...Michigan voters just don't embrace Romney. Only 45% have a favorable opinion of him to 49% with an unfavorable one. They don't accept Romney as one of their own either- only 34% consider him to be a Michigander to 57% who do not... definitely not helping Romney in Michigan is the position he took on the auto bailout. 53% of voters think Obama has been better for the automotive industry in the state compared to only 31% for Romney. And this is something voters care about- 80% of voters say the candidates' record on the automotive industry is important to them, and 48% deem it to be 'very important.'

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The Republican convention doesn't seem to have done Romney a lot of good in Michigan. Only 30% of voters say it made them more likely to support the GOP this year while 35% say it actually made them less likely to do so, and an equal 35% say it didn't make a difference to them either way...