Bernie Sanders: 'I disagree with Hillary Clinton on virtually everything'

US Sen. Bernie Sanders (I-Vermont) appears to be taking off his gloves and drawing his sharpest contrast yet with his chief Democratic presidential primary rival, former US Secretary of State Hillary Clinton.

"I disagree with Hillary Clinton on virtually everything," Sanders told The Boston Globe's editorial board, according to a story published Thursday.

He continued: "What is important is to look at the record, the track record that Hillary Clinton has had for her long and distinguished career as a public figure."

Sanders pointed to two issues as proof: the Keystone XL pipeline and the Trans-Pacific Partnership. Clinton long refused to weigh in on the pipeline until she revealed her opposition in September. And she repeatedly supported the Pacific Rim trade deal as secretary of state, butshifted her stance last month to opposition. Liberal activists oppose both issues.

"How many years do you have to think about whether or not we excavate and transport the dirtiest fuel in the world?" Sanders told The Globe of the Keystone pipeline. "It didn't take me too long to think about that."

Additionally, Sanders told the Boston newspaper and The Wall Street Journal that there are still legitimate questions to be answered about Clinton's controversial email practices at the State Department. Clinton exclusively used a private email server and account for her government work, which she now says was a mistake.

During the Democratic debate last month, Sanders famously defended the Democratic front-runner by declaring that the "American people are sick and tired of hearing about your damn emails!"

But Sanders insisted that he didn't "let her off the hook" and says now that he only had a few seconds to make his point during the debate.

"There is a process going on in this country. There is an investigation. The FBI is doing what it is doing," Sanders told The Globe, referring to the investigation into whether any information was mishandled in connection to Clinton's server. "Whatever happens with the email thing will happen. I don't know. I'm not an expert. Let it take place."

REUTERS/Lucy Nicholson

Sanders directed yet another tough comment Clinton's way as he filed to run in the New Hampshire primary Thursday, according to The Washington Post.

"You ready to kick some Republican butt, Bernie?" someone in the crowd asked him.

The senator replied: "There's some earlier butt we have to deal with."

For its part, the Clinton campaign fired back at Sanders after his interview with The Journal, in which he also said that her policy reversals over the years "does speak to the character of a person."

Clinton spokesman Josh Schwerin told the paper that Sanders was flip-flopping on his vow not to launch personal attacks against his rival.

"This has and will remain a campaign about issues for Hillary Clinton, and that's what she'll continue to talk about on the trail," Schwerin told The Journal.

He continued: "It's disappointing Sen. Sanders and his campaign strategists have chosen to change direction and engage in the type of personal attacks that they previously said he wouldn't do."