Newt Gingrich has chided House Speaker Paul Ryan for his hesitancy in endorsing presumptive Republican nominee Donald Trump, saying that "if you are not for Donald Trump, you are functionally helping Hillary Clinton, it's just that straightforward."Appearing onSunday radio show on AM 970 New York hosted by John Catsimatidis, the former House speaker said he thought "the moment to say, OK, we have the leader of the team, let's pull the team together, let's go beat Hillary has arrived."Ryan and Trump met face to face on Thursday in an attempt to patch up their differences, after which the Speaker praised Trump but still did not give his endorsement.Stressing that "we are living in a period of remarkable chance," Gingrich said that various elements of disillusionment with Washington from both the right and left "have come together to create the most insurgent candidate of my lifetime Donald Trump."Commenting on Clinton's e-mail scandal, Gingrich said that "it's a little hard to imagine the FBI being this tenacious and this determined if there's nothing there" and said that "the weight of evidence is that any other person who would have done these things would already be in a jury trial on criminal charges."Gingrich, who has been touted as a possible running mate for Trump, was not asked about that by Catsimatidis, but told Fox News Sunday that he's open to the idea, although it's not "an automatic 'yes.'"Gingrich said he remains optimistic about the future of the United States despite the many difficulties facing the country, saying, "I have enormous faith that the American people are bigger than our problems."