When the 2016 election campaigns got underway, Conway had been acquainted with Donald Trump for years, because she lived in Trump World Tower from 2001 to 2008 and sat on the condo board.[8] Yet she initially endorsed Ted Cruz in the 2016 Republican presidential primary and chaired a pro-Cruz political action committee known as Keep the Promise I, which was almost entirely funded by businessman Robert Mercer.[46][47] Conway's organization criticized Republican presidential candidate Donald Trump as "extreme" and "not a conservative".[9][10] On January 25, 2016, Conway criticized Trump as "a man who seems to be offending his way to the nomination."[48] On January 26, Conway criticized Trump's use of eminent domain, saying "Donald Trump has literally bulldozed over the little guy to get his way."[49]

In mid-June 2016, Cruz suspended his campaign and Conway left