I understand the cost concerns based on speculation. Caucus supporters say it won't cost much. Primary supporters think otherwise.
From Saul Anuzis:
After several months of discussions between state committee members, county chairs and party activists…the State Committee’s Policy Committee unanimously passed a resolution recommending a closed primary to the full State Committee.
The Committee considered the pros and cons of a caucus, convention and closed primary. Every possible factor was considered and there was a significant amount of input from activists around the state. Committee members representing EVERY congressional district solicited advise from their members.
The Committee also recommended using the 2008 Apportionment method to allocate delegates. That is winner take all by congressional district and proportional for the at-large delegates based on the overall statewide vote. A candidate would have to get a minimum of 15% to qualify for any delegates.
The final vote is in August's state committee meeting. I'm not on state committee, so I don't have a vote. If I did, I'd have to look closely at any language dealing with registration, challenges, and alternatives. I'd support this over an open primary. I think conventions are real bad from a PR standpoint and strongly oppose them for presidential nominations. They are good for "smaller" offices.
I support a caucus. It's not perfect and would take a lot of work. A lot of the old timers oppose caucuses based on 1988's fight between Jack Kemp, George HW Bush, and Pat Robertson. I wasn't active then, but have heard plenty of stories. It's a different era, with different people and candidates. Top down stuff backfires a lot more these days in the age of the internet.
Opponents of the caucus have logistic worries, but Michigan has had caucuses for a long time. The last one was in 2004. It was done by the democrats. There was some controversy, but mostly with candidates ignoring Detroit.
I'll take a "closed" primary over a convention (too exclusive) and over a true open primary, but I think caucuses are the cleanest way in a non party registration state to determine that party's nomination for president.
Edited to add. I'm hearing, but haven't confirmed that the policy committee's decision if enacted, would have voters declaring their ballot at the polling place. If that is true, than this is not a closed primary at all but an open primary. I oppose that 100%. If there is going to be a primary, there needs to be more safeguards than that, and the policy committee's recommendation would need to be amended.