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 PortmanRob PortmanGOP debates going big on tax reform Who is Tim Ryan? A closer look at Pelosi’s challenger Battle for the Senate: Top of ticket dominates 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.