Watch: Republican gubernatorial candidate debate at Mackinac Policy Conference

GOP candidates for governor debate at Mackinac Policy Conference

Republican candidates Tudor Dixon, Ralph Rebrandt, Kevin Rinke, and Garrett Soldano talk about their election platforms in preparation for the August primary. with hopes of unseating incumbent Gov. Gretchen Whitmer in November.

FOX 2 - Four Republican candidates for governor squared off in a debate at the Mackinac Island Policy Conference hosted by the Detroit Regional Chamber.

Tudor Dixon, Ralph Rebandt, Kevin Rinke and Garrett Soldono will took part in the debate.

The highest-profile candidate - James Craig - won't be in the mix however after a judge declined to put the former Detroit police chief on the Republican ballot.

Republican candidate Tudor Dixon

He was the third candidate to lose a court challenge after election staff said campaign petitions were marred by fraudulent signatures.

Court of Claims Judge Elizabeth Gleicher said she must abide by a Michigan appeals court decision released Wednesday that kept two other Republicans, Perry Johnson and Michael Markey, off the Aug. 2 ballot.

Republican candidate Ralph Rebrandt

In Craig’s case, election staff said he appeared to have only about 10,200 valid signatures after subtracting 9,879.

He argued that the state had an obligation to go line by line, comparing signatures to the eligible voter file before striking them. Only 20% of the suspicious signatures were formally checked.

Republican candidate Kevin Rinke

But the appeals court said that wasn’t necessary.

Republican candidate Garrett Soldano.

"The board ... had a clear legal duty to investigate, but it did not have a clear legal duty to conduct a comparison of each fraudulent signature against the qualified voter file," the court said in a 3-0 opinion in Johnson’s case.