"He's going to be too busy," Carson says.
"It’s like eating a watermelon and saying, ‘I love African-Americans,' " Bush said.
Trump has caught intense criticism over tweets he's shared.
"He is being treated badly!" Trump tweeted.
"I wasn't sitting up there thinking, 'Oh my god, what have I done?'"
"Bless your heart," Haley told Trump.
Gilmore noted he outlasted Rand Paul and Rick Santorum in the GOP presidential race.
"My experience in Iowa was a great one," he tweeted.
Hours after the Twitter poll was posted to his account, Trump said he would not participate.
Mario Trujillo 12/07/15 10:32 AM EST
Twitter released a list of the most popular items on the social media platform this year....