Disgraced former South Carolina Gov. Mark Sanford on Tuesday was invited back on his pal Joe Scarborough's MSNBC morning show on voting day in South Carolina's 1st Congressional District and refused to directly answer a question about lying to his constituents and cheating on his wife, telling co-host Mika Brzezinski that she had also made "some mistake" that was similar.

Last month, Comedy Central host Stephen Colbert had ripped Morning Joe for essentially providing a infomercial for Sanford after his primary win, at one point noting that "Woodward and Bernstein may have had Deep Throat, but [MSNBC contributor] Mike Barnicle is doing something similar to Mark Sanford."

In a follow up interview on Tuesday, Brzezinski was careful to point out that Sanford's opponent, Elizabeth Colbert Busch -- who is also Stephen Colbert's sister -- had declined an invitation to be on the show.

"For those who agree with your opinions and your record and your opinions on debt the deficit and governing, but are concerned about how you left office and what happened, how do you answer the question, can voters trust you?" Brzezinski asked the former governor.

"Well, I'd turn it around to you, Mika," Sanford replied. "I'd say, I guarantee -- we don't know each other at a personal level -- but I guarantee you, you've made some mistake in your life wherein somebody could raise that very question to you. I could turn it around to Joe. I could turn it around to anybody on the set and say, one offense does not define your life."

"What if I screw up every day?" Scarborough wondered. "Will people forgive me if I make horrible mistakes every day? Is that okay?"

"Well, I guess it would be tough if there's a pattern every day," Sanford admitted. "It might be stretching it with the scope and nature of human forgiveness."

Barnicle pressed the South Carolina Republican about how he would vote on a bill to expand background checks to gun shows and Internet sales.

"I'm a big Second Amendment person, and so, you know, the present bill with [Sens.] Manchin and Toomey, I would have voted no," Sanford insisted. "Because I think you really got to dig down deep to define what a gun show is. If it's a couple guys in the back of a pickup truck trading a gun, I don't know that fits a -- quote -- a gun show."

Watch this video from MSNBC's Morning Joe, broadcast May 7, 2013.