"most of the rest of Washtenaw is marginal anyway."
Heck, every county in the district (save for Republican Branch and Hillsdale Counties) are pretty marginal.
"The GOP calhoun townships will balance it out.(although I don't know which ones they are - probably marginal if near Battle Creek)"
Looking at the map of the district you posted, and comparing it to a township map of Calhoun County, I see that the townships placed in the 6th district were Leroy (which gave Bush 55.7% and a 929-697 margin over Gore) and part of Athens (the entire township gave Bush 57.5% and a 636-442 margin over Gore, but I don't know what the portion in the 7th CD gave Bush).
For township maps of Michigan, you can go to
http://www.michigan.gov/cgi/0,1607,7-158-12540_13083-31058--,00.html and click on the county you want.