The May 28 issue of the Lake Forester (the daily newspaper of Lake Forest, Illinois) has this editorial, criticizing the legislature for retaining the state’s primary in February.
No state has ever had its congressional primary that early in a mid-term year. Illinois SB 46, co-sponsored this year by eight State Senators, would have moved the 2010 primary to June, but it failed to make any progress, and the legislature is close to adjournment.
Note that Maryland had its congressional primary in 2008 in February rather than its usual September date.
Thanks, Rob. I amended the post.