Donald Trump was absent from the Sunday talk shows for the first time in weeks. But those Republican hopefuls who did sit down for network interviews still had to grapple with the surprise Republican front-runner.

Perhaps no candidate has suffered because of the Trump surge more than Wisconsin Gov. Scott Walker, who was asked on NBC's “Meet The Press” about what he could do to regain momentum he was seeing before the real estate magnate took off.

“It's hard work. It's going out. It's doing town hall meetings,” he said. “For us, I think the biggest spark for us is getting the message out that now is not the time to put in place someone who hasn't been tested before.”

Republican Louisiana Gov. Bobby Jindal argued in a pair of interviews that as voters began taking their choice more seriously after the summer months, the landscape will change.

“I think after we get past this summer of silliness and insults, the voters are going to begin to look at who is prepared to do the job,” he said on ABC's “This Week.” “What I see is that voters haven't committed to any candidate yet. In Iowa, in these early states, they're kicking the tires, they're asking the tough questions. This is a wide open race.”

New Jersey Gov. Chris Christie insisted on “Fox News Sunday” that Trump's standing was a reflection of the crowded field, and that he would continue to focus on substantive policy proposals. He specifically dismissed Trump's immigration plan as “simplistic.”

All three also faced questions about one of the issues Trump has focused on most: immigration.

Christie defended saying that the government should use technology to track illegal immigrants as companies like FedEx do to track packages.

“My point was this is once again a situation where the private sector laps us in the government with the use of technology,” he said. “We should bring in the folks from FedEx to use the technology to be able to do it. There's nothing wrong with that. And I don't mean people are packages. So, let's not be ridiculous.”

Walker, meanwhile, said he's even heard voters in New Hampshire advocating tougher immigration enforcement at the Canadian border.

“Some law enforcement folks that brought that up to me at one of our town hall meetings about a week and a half ago. So that is a legitimate issue for us to look at,” he said of building a wall on the U.S.-Canada border.

Jindal said the U.S. has a “dumb” immigration policy now.

“We need to insist that folks who come here come here legally, learn English, adopt our values, roll up our sleeves and get to work,” he said. “Immigration without integration is not immigration; it's invasion. My parents are proud of their Indian heritage, but they came here to be Americans and they love this country.”