I looked up some time ago where the Kentucky electoral law bans electoral fusion in this state, and then misplaced the link. It's KRS 118.405: No candidate's name shall appear on any voting machine or absentee ballot more than once, except that a candidate's name may appear twice if he is a candidate for a primary or a regular election and also a candidate to fill a vacancy in the same office required to be filled at a special election, when the special election to fill a vacancy is scheduled for the regular election day.
KRS 118.015 provides some definitions: A "political party" is an affiliation or organization of electors representing a political policy and having a constituted authority for its government and regulation, and whose candidate received at least twenty percent (20%) of the total vote cast at the last preceding election at which presidential electors were voted for; "Political organization" means a political group not constituting a political party...but whose candidate received two percent (2%) or more of the vote of the state at the last preceding election for presidential electors; and..."Political group" means a political group not constituting a political party or a political organization... KRS 118.105 informs us that any political organization not constituting a political party as defined in KRS 118.015 may make its nominations as provided in KRS 118.325. And it appears that KRS 118.345, preventing defeated primary candidates from having their name on a regular election ballot, would prevent something like what Connecticut Senator Joe Lieberman did in 2008.
According to the 2008 Kentucky election results, Independent Ralph Nader received 0.8% of the vote, Libertarian Party nominee Bob Barr received 0.3% of the vote, and Constitution Party nominee Chuck Baldwin received 0.3% of the vote.