"Please cease using Seth as a political football in predetermined partisan narratives," the family said.
"His instinct is, 'I'll outbluff you,'" Gingrich said of Trump.
The president will pick Callista Gingrich, Newt Gingrich's third wife, before he meets Pope Francis, say reports.
Washington Post-ABC poll shows Hillary Clinton by 8 points; Reuters/Ipsos poll shows the Democratic candidate up by 3.
By choosing Mike Pence, Donald Trump gives his campaign a harder ideological edge.
Mike Pence's absence from the RNC speakers' list has increased speculation that he will be Donald Trump's running mate.
Mike Pence, Newt Gingrich and Chris Christie are apparently Trump's top contenders for the VP spot.
Newt Gingrich's 1994 version was limited in scope and rode an anti-Clinton wave. The New York Mayor is trying something harder.
Former U.S. House of Representatives Speaker Jim Wright, a Texas Democrat known for hardball politics who quit amid accusations of financial impropriety, has died at the age of 92
Gingrich thinks the House leadership attacked outside conservative groups to win next year's elections.