 -- The former governor of New Mexico, Bill Richardson, slammed GOP presidential candidate Donald Trump in an interview with ABC News, calling his positions on immigration “racist” and “ludicrous.”

Richardson, who has endorsed Hillary Clinton for president, also weighed in on the 2016 race, saying he did not think Vice President Joe Biden would ultimately enter the race for president.

See more of our conversation below.

1] Former Gov. Ed Rendell told the New York Times that Hillary Clinton’s campaign has been “incredibly tone-deaf” on the email issue. Do you agree?

Richardson: I don’t agree with tone-deaf statement. I do believe it could have been handled better, but the media has been over-obsessive about this controversy and most Republicans have tried to exploit the issue politically. Earlier in the flap, I would have said, "I turned to a private email system because I did not want to be hacked nor did I want my confidential and sensitive discussions with foreign leaders on front pages because of WikiLeaks." I would also emphasize that other secretaries of state like Colin Powell followed this practice and it was perfectly permissible and legal at the time. Nonetheless, I would also say it was a mistake to have followed this course of action given the controversy.

2] Vice President Joe Biden has not ruled out a potential bid for the presidency. Why would Hillary Clinton be a better candidate than Biden?

Richardson: Both Hillary and Biden are strong centrist-progressive candidates who could win a general election. Hillary would have an edge in the primary because of her superior organization, fundraising strength and the fact that she would be galvanizing women voters by becoming the first female president. In the end, I do not think Joe Biden will enter the race because of personal issues, such as his family situation. But he would be formidable if he entered because of his genuineness and his stellar record as vice president.

3] Sen. Bernie Sanders is making gains on Clinton in Iowa. Are you worried about her ability to maintain her lead in that state?

Richardson: I predict Clinton will narrowly beat Sanders in Iowa because of her superior organization in a caucus setting. Sanders has attracted a sizable progressive base in a state that has perhaps the most liberal Democratic constituency of all fifty, yet devoid of minorities and other Hillary-based voters. Once the primaries move out of Iowa and New Hampshire, Hillary’s strength among women, African Americas and Hispanics, and other activist voters will emerge and she will coast to the nomination.

4] Turning to the GOP, what do you make of Donald Trump's presence in the race? What explains his success so far?

Richardson: I am flabbergasted by Trump’s notoriety in the race. He is appealing to a frustration and an anti-establishment climate in the Republican electorate and little else. His celebrity and outrageous positions are tapping into a tea party faction that is propelling him to twenty plus percent [in the polls] but no higher. And the press is giving him undeserved attention and not scrutinizing his ridiculous positions on most issues.

5] What do you make of Trump’s immigration proposal?

Richardson: Trump’s immigration positions do not deserve a response because they are so outlandish. If you force me to give you three words to describe them they would be: ludicrous, impractical and racist.