Newly declared presidential candidate Rep. Seth Moulton is accusing Republican President Trump of “dereliction of duty” over what the Massachusetts Democrat calls his administration’s unwillingness to address the threat of Russian tampering with America's presidential elections.

And Moulton – one of the ringleaders in last year’s failed effort by a small group of congressional Democrats to prevent Nancy Pelosi from regaining the House speakership – argued that his party “frankly…made a mistake by waiting until now” to consider impeachment.

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The long-shot for the Democratic presidential nomination made his comments during an appearance Wednesday morning at ‘Politics and Eggs,’ a must stop in the first-in-the-nation presidential primary state of New Hampshire.

The Marine veteran who served four tours of duty in the Iraq war is making defense and national security top issues in his White House bid. He told the audience that “I’m going to confront President Trump on these issues of safety and security of leadership around the globe where I think he’s weakest.”

And spotlighting his unsuccessful bid to keep Pelosi from regaining the speaker’s gavel, Moulton touted “my willingness to challenge the Washington establishment will make me a much stronger nominee against Donald Trump.”

Pointing to last week’s release of a Special Counsel Robert Mueller’s Russia report, Moulton told reporters “the one unmistakable conclusion of this report is that Russian interfered in this election to undermine our democracy and that Vladimir Putin wanted Trump to get elected president.”

And he slammed the White House, saying “this administration has been completely unwilling to address this major national security threat to the United States” and accusing Trump of “a complete dereliction of duty on the part of the commander in chief.”

“He's more concerned about his own personal reputational security than the security of the United States of America,” he charged.

Moulton joined his 2020 rivals in arguing that Trump obstructed justice and called for impeachment hearings. That’s at odds with Pelosi, who said on Tuesday that she was "not there yet" in supporting the initiation of impeachment proceedings.

Moulton said “we should be advancing articles of impeachment and debating them. We should be putting on paper the charges against the president and then having debate across the aisle with hearings, with witnesses, with subpoenas and documents, about whether or not the president deserves to be impeached under these charges. …That’s the job of Congress. That’s our constitutional responsibility as a check on the executive.”

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And Moulton took aim at House Democratic leaders, saying “I think we should have started this a while ago. Both sides of the aisle here [are] failing to step up and do this.”

“I understand there’s a debate right now within my party and it’s a very divisive debate. People think this isn’t the right time or what not. They think it’s not good for our politics is basically the argument for not doing it right now. But we have a higher calling than our politics. It’s called the Constitution,” he spotlighted.

For his part, Trump on Wednesday blasted Democrats ramping up their investigations into him in the wake of the Mueller report. “I say it’s enough. Get back to infrastructure, get back to cutting taxes, lowering drug prices. Really, that’s what we should be doing,” Trump said.

Moulton also took aim at the single-payer "Medicare-for-all" health care proposal being pushed by many of his rivals for the nomination.

“I don’t think it’s right to take every American, many of whom are happy with the health care that they have, and force them on some government plan designed in 1963,” Mouton told reporters.

Moulton’s appearance at ‘Politics and Egg’s was his last stop in a two-day swing through New Hampshire.

The Republican National Committee, meanwhile, described Moulton as a mere “2020 wannabe.”

RNC spokesperson Mandi Merritt told Fox News that Moulton’s “desire to raise taxes, implement the socialist Green New Deal, and diminish New Hampshire’s voice by scrapping the Electoral College makes him just another out-of-touch Democrat who will ultimately fall short.”