In the early stages of the race for the Republican gubernatorial nomination, candidates have focused their campaigns on criticizing Gov. Dannel P. Malloy and state Democrats. But before any of them can face the incumbent governor in his bid for re-election, they first must convince their party that they are the best candidate for the job and the best shot the GOP has at taking back the governor's office in November's election. Here is a primer explaining where each candidate stands on some of the key issues, showing where they overlap and where they differ in their visions for Connecticut. PHOTO: Republican candidates for governor Danbury Mayor Mark Boughton, Senate Minority Leader John McKinney, Avon attorney Martha Dean, Shelton Mayor Mark Lauretti and former West Hartford Town Council member Joe Visconti met at the Mark Twain House and Museum for a debate Friday sponsored by The Hartford Courant and FOX CT.