He says his political enemies have been conducting a 'stealth' [='secret'] campaign to block his nomination.
The fox uses 'stealth' and cunning to hunt its prey.
a 'stealth' bomber/fighter
(..) all these lights down. Hey, guys, keep your IRs pointed up for the gunship that's hopefully fucking coming. Time for stealth has passed. Viper, keep the perimeter floodlights on. Shut off the interiors. Roger that. Roger that. (..)2016 13 Hours