Gov. Christie on Sunday said it wasn't fair to compare his scant use of a private email account to conduct government business during the Bridgegate scandal to Hillary Rodham Clinton's exclusive use of a private server while she served as secretary of state.

Appearing on "Fox News Sunday," Christie, a Republican presidential candidate, asserted that there were sufficient grounds to investigate Clinton, the front-runner for the Democratic presidential nomination, for potential mishandling of classified information.

Host Chris Wallace then noted that Christie had exchanged 12 text messages with an aide in December 2013 as New Jersey's Democratic-controlled Legislature investigated the George Washington Bridge lane-closure scandal.

Those texts appear to have been deleted.

The one e-mail exchange involving Christie made public by the legislative committee investigating the matter showed the governor corresponding with his press secretary about how to craft a statement in praise of David Wildstein as he prepared to resign from the Port Authority of New York and New Jersey.

(Wildstein has pleaded guilty to charges in the bridge case and is cooperating with the government.)

"My press secretary sent it to my private e-mail account, I'm sure inadvertently, and I responded to it," Christie said Sunday. (He indicated other e-mails' of his hadn't been released.)

"We cannot compare that, can we, to someone having a private email server in the basement of their home, where they did all of the government business on a private email server in their basement?

"We can't compare that to having national security secrets -- we're really not, Chris, are we? -- comparing a press release to having national security and classified documents running through a server that's not protected by the federal government that could be hacked by the Russians, the Chinese, or just a group of 18-year-old hackers who want to have some fun?"

Christie added that he conducted state business on his government account.

"Everything I've done as governor has been an open book," he said. "I've answered every question anybody's had. …Can you hold Mrs. Clinton to that standard? I'll tell you something, I haven't seen it."

Clinton has said she did not exchange e-mails with classified information on her unsecure account. Investigators have since determined that some of the emails did contain classified information, however, and the FBI is investigating the matter.

Christie also lashed out at Clinton for saying in Cleveland last week that while she expected terrorist groups to espouse extreme views on women, "It's a little hard to take from Republicans who want to be president of the United States."

"That's a disgrace, and she's a disgrace," Christie said Sunday.

"She's a disgrace for saying that, for comparing Republicans to terrorist groups," he said. "That's awful."

He also defended his plan to track immigrants with the same technology FedEx uses to track packages.

"Let's use the same type of technology to make sure that 40 percent of the 11 million people here illegally don't overstay their visas," Christie said.

"If FedEx can do it, why can't we use the same technology?" he added.

Democrats attacked Christie after he made similar remarks in New Hampshire on Saturday.

"To compare immigrants and Americans to tracking a FedEx package is a new low of lows for the Republican field," Democratic National Committee spokeswoman Christina Freundlich said late Saturday.

"The only tracking numbers that Christie should be concerned with is his poor job creation numbers and record nine credit downgrades."

Addressing criticism, Christie said Sunday, "And I don't mean people are packages, so let's not be ridiculous."