SEATTLE — The race for governor of Alaska took a decided turn into the wild on Tuesday when the Democratic candidate, Byron Mallott, said he would withdraw and run instead for lieutenant governor alongside an independent candidate, Bill Walker.

The decision means that for the first time since Alaskan statehood in 1959, no Democrat will be on the ballot for governor.

Mr. Mallott said he became convinced, after days of soul-searching and analysis of the polling data, that reshuffling the deck was the only path to victory over Gov. Sean Parnell, a Republican who is seeking his second term.

The unity ticket with Mr. Walker was announced in Anchorage on Tuesday afternoon after a weekend of negotiations between the campaigns, and hours before the deadline for changes to the November ballot.