Judge me by what I can do for America now, rather than only by my mistakes in the past, Republican presidential candidate Newt Gingrich said Sunday.

The former House speaker, who announced his candidacy last week, told NBC's "Meet the Press" that he has made mistakes in life, including an adulterous affair that led to one of his two divorces.

Now the American people must decide whether he's the right person to lead the country at what Gingrich called a crucial moment in its history. 

Gingrich, who turns 68 in June, was first elected to Congress from Georgia in 1978. He rose to the second spot in the House Republican leadership, and was instrumental in helping to craft the 1994 Contract with America -- a conservative blueprint that helped the Republicans take control of the House.

He then became House speaker, but after a disappointing GOP showing in the 1998 congressional elections, Gingrich retired in 1999.

His push for President Bill Clinton's impeachment for allegedly lying to a federal grand jury after an affair with a White House intern got labeled as hypocrisy when news emerged that Gingrich also had an adulterous affair that broke up a previous marriage. Now divorced twice, Gingrich conceded Sunday he made decisions that should be questioned by voters assessing him as a candidate....