"This is like the 'Seinfeld' candidacy," Cruz spokesman Rick Tyler said on CNN's "Erin Burnett OutFront
"It's about nothing. The whole campaign is about nothing."
"I didn't hear one substantive piece of anything, of policy there, nothing about immigration, nothing about job creation, nothing about what's going on in North Korea right now, nothing about defeating [the Islamic State in Iraq and Syria]," Tyler said. "I mean, this is amazing. This is a 'Seinfeld' candidacy. It's about nothing."
Republicans have long criticized Trump for relying on his personality instead of detailed policy proposals during his media-oriented campaign.
Trump late Wednesday held his first major rally since winning the New Hampshire primary earlier this week. He and Cruz are battling for a win in South Carolina, which holds the next Republican contest on Feb. 20, following Iowa and New Hampshire, where Cruz and Trump won, respectively.