According to Wiki. The question is, Is the Green Party's nomination process legitimate even though the person will primarily be chosen through state conventions without a popular vote of the people? If McKinney is chosen through the process, should Green Party members respect the result, or overthrow it because Nader has more experience, name recognition, and a better chance to win?
"Green Party primaries in Arkansas, California, Illinois, and Massachusetts were held on February 5, 2008. California and Massachusetts were won by Ralph Nader, while Illinois and Arkansas were won by Cynthia McKinney. Washington, DC held the DC Statehood Green Party primary on February 12 which was won by McKinney as was the February 19 Wisconsin Green primary <21>. On May 13 Mckinney won the Nebraska primary with 57% of the vote <22>. The West Virginia Mountain Party will hold the last green primary on May 13.
The Green Party of Pennsylvania will hold county caucuses from April 24 through May 10.
Other States will hold caucuses or will establish their candidate choices via state conventions. Most states will allocate their delegates proportionally based on the support for various Green Party presidential candidates."
http://en.wikipedia.org/wiki/Green_Party_(United_States)