Since reality-show stars these days are social-media pros, it is no surprise to see both girls tweeting a picture with Atkins before the event. Magrane tweeted on Monday that it was "fun times."

But someone else was excited to see Atkins: Sen. Rob PortmanRobert (Rob) Jones PortmanHarvard biz school honors Wilbur Ross GOP senators blast White House aide over trade remarks Community development impact remains clear with NMTC post-tax reform MORE (R-Ohio) tweeted a picture behind the scenes with the "If You're Going Through Hell" singer on Sunday night.

Other previous "Idol" contestants expected to perform at the GOP convention include Danny Gokey, Taylor Hicks and Ayla Brown.