This is a big endorsement from Senator Mike Lee. It puts him in direct opposition to Senator Mitch McConnell. McConnell is adamantly opposed to Stutzman if only because Marlin Stutzman has a well known track record of defying John Boehner. McConnell knows Stutzman would not bend over for McConnell.
Mike Lee endorsing Stutzman also makes very clear who the conservative is in the race.