WASHINGTON (AP) — President Donald Trump on Monday lashed out at Democratic Sen. Richard Blumenthal, calling him a “phony Vietnam con artist” after the lawmaker expressed concerns about the Justice Department’s pursuit of leakers and embraced a special counsel’s probe of Russia meddling in the election and possible collusion with Trump campaign officials.

In a series of tweets from his vacation in New Jersey, Trump dismissed the “hoax Russian collusion” and revived a 2010 embarrassment for Blumenthal. The Connecticut lawmaker, a Marine Corps reservist during Vietnam, had to apologize for saying he had served in the war.

“Interesting to watch Senator Richard Blumenthal of Connecticut talking about hoax Russian collusion when he was a phony Vietnam con artist!” Trump tweeted.

“Never in U.S. history has anyone lied or defrauded voters like Senator Richard Blumenthal. He told stories about his Vietnam battles and…….conquests, how brave he was, and it was all a lie. He cried like a baby and begged for forgiveness like a child. Now he judges collusion?”

Trump’s criticism came shortly after Blumenthal, a member of the Senate Judiciary Committee, was interviewed on CNN. The senator discussed several topics, including the Justice Department’s crackdown on leakers, new sanctions on North Korea and reports that special counsel Robert Mueller has impaneled a grand jury in his inquiry into Russia meddling and potential ties to the Trump campaign.

“I’m very concerned that the Department of Justice is weaponizing these laws for its personal and political ends, and specifically for the White House’s purposes,” Blumenthal said. He warned of a “chilling effect on the press and whistleblowers.”

The two-term Connecticut senator and former state attorney general credited the media for its reporting on the Trump administration. He said Mueller’s investigation must be pursued.

“The impanelment of the grand jury shows that Bob Mueller is pursuing this potential wrongdoing by the Russians, the attack on our democracy, seriously and diligently. There is no minimizing … that attack by the Russians,” Blumenthal said, before pointing out the “potential collusion by the Trump campaign and then obstruction of justice.”

He said “that investigation must be pursued.”

It wasn’t the first time that Trump had raised the issue of Blumenthal and Vietnam. Earlier this year, Trump accused Blumenthal of misrepresenting Neil Gorsuch’s comments from a private meeting. Blumenthal said Gorsuch, who was confirmed to the Supreme Court, had told him that he found the president’s attacks on the judiciary “disheartening” and “demoralizing.”

In response, Trump said during a luncheon with senators that Blumenthal had misrepresented Gorsuch. “His comments were misrepresented. And what you should do is ask Senator Blumenthal about his Vietnam record that didn’t exist after years of saying it did,” he said.