Steve King probably won’t endorse anyone officially, and neither will any Iowa US congressman, senator, or the governor. They consider themselves hosts to the broader party.
However, it is well-known that King is a big fan and friends with Ted Cruz. Gov. Branstad and Sen. Ernst have both been unofficially favoring Walker. Ernst will probably lean Cruz. Branstad isn’t crazy about Jeb, so might lend off-the-books support to Rubio and might even prefer Christie if fat boy could be resurrected.
Vander Plaats has already been leaning Cruz, based on the the strong Cruz ground game in Iowa.
“Sen. Ernst have both been unofficially favoring Walker.”
Has Senator Ernst made anyone squeal yet?
Steve King endorsed Fred Thompson in 2008— but from what I read, he’s undecided as to Trump and Cruz. His former chief of staff is directing Trump’s Iowa campaign, and his son is involved with one of Cruz’s Pacs.