Allied super-PACs supporting Sen. Ted CruzTed CruzLimbaugh avoids endorsing Trump Jake Tapper rips 'shameful' Trump comments Kasich moves to hold onto his delegates MORE (R-Texas) have released a new ad that mocks Sen. Marco RubioMarco RubioKasich moves to hold onto his delegates Pressure builds from GOP to delay internet domain transition The Hill's 12:30 Report MORE's (R-Fla.) interest in fantasy football to portray him as unserious on national security issues.
The 30-second television spot from Keep the Promise suggests Rubio is not ready to be the commander in chief.
"What would Marco Rubio's leadership look like?" the ad asks, before cutting to video of a smiling Rubio talking on the phone while staring at a laptop.
"Yeah I know I have a debate, but I got to get this fantasy football thing right," Rubio says in the video, originally released by his campaign in a spoof of his preparation for an October debate.
"Tell Marco Rubio: America can't afford to gamble with its safety," the Cruz ad then states.
Rubio's campaign hit back at the video, with an aide tweeting, "Wonder which Cruz-Simpson character @tedcruz PAC thinks is best prepared to lead the country?" and linking to a video of Cruz doing impressions from "The Simpsons."
Cruz and Rubio, who have largely avoided front-runner Donald TrumpDonald TrumpLimbaugh avoids endorsing Trump Jake Tapper rips 'shameful' Trump comments Muslim lawmaker: Muslims for Trump is like chickens for Colonel Sanders MORE, have been battling for months on national security and immigration heading into the first GOP primary contests next month.
Cruz leads polls in Iowa, while Rubio is in the upper tier of candidates in all of the early-voting states, according to polls.
The video is part of a $1 million advertising blitz by the Cruz super-PACs, running for two weeks starting Tuesday in Iowa, according to a representative from the group.
Those behind the TV ad say it will be released digitally in other early-voting states, including New Hampshire, South Carolina and Nevada, along with radio ads hitting Rubio on immigration.