A disgruntled Sen. Rand Paul walked out of the Senate on Thursday and held a press conference after Chief Justice John Roberts refused to read his question aloud during the impeachment trial proceedings.

After calling on Paul, the first Republican senator to be recognized Thursday, and reading his question to himself, Roberts said: "The presiding officer declines to read the question as submitted."

Paul's question had reportedly been rejected Wednesday because it named the alleged whistleblower who claimed President Donald Trump had threatened to withhold military aid from Ukraine until its leaders would agree to investigate Hunter Biden, son of Democratic presidential hopeful and former Vice President Joe Biden.

More:How Paul went from calling Trump an 'orange windbag' to his disciple

Roberts had told senators that he will not read aloud the alleged whistleblower’s name or any questions that might reveal the person's identity.

Paul was reportedly miffed by Roberts' decision Wednesday, and his office said before proceedings began Thursday that he would "insist on his question being asked."

After the decision to reject his question on Thursday — which Paul called "incorrect" — the Kentucky Republican left the Senate and read the question, which named the alleged whistleblower, at the press conference.

The senator also posted the question on Twitter minutes after Roberts declined to read it aloud.

From Wednesday:Paul blocked from asking question that names whistleblower

In the press conference, Paul said his question "made no reference to any whistleblower.” Rather, he said, the question asked about Democratic "partisans" left over from Barack Obama's administration conspiring to impeach Trump.

Paul said that he did not receive any justification from Roberts regarding his decision but that he decided not to ask to overrule the chief justice because he did not want to "delay the proceeding."

Senate leaders requested that senators remain in their seats during the impeachment proceedings. However, leaving the chamber during the trial and speaking with reporters — like Paul did — is not explicitly prohibited in the official Senate trial rules.

The whistleblower's identity has not been revealed or verified publicly, which is why The Courier Journal and USA TODAY are not publishing the person's name or Paul's question.

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Paul has persistently urged that the alleged whistleblower be outed publicly, and he used the name of the alleged tipster in two separate interviews with other news organizations in November.

After doing so, people questioned the legality of his comments. But experts on whistleblower protection law said at the time that punishment would be difficult.

Dan Meyer, an expert on the rules protecting whistleblowers in the intelligence community, said at the time that there were essentially no penalties for Paul's actions, as there is no general rule barring most senators from disclosing the name of the whistleblower.

The one exception is the Senate Intelligence Committee, Meyer said, but Paul is not a member of the panel.

Some Republican senators have not taken kindly to the contents of Paul's questions. Sen. Lindsey Graham, R-S.C., said Thursday morning that the identity of the whistleblower should not be revealed by Paul's question on the Senate floor.

“Not in this environment,” he told reporters. “Later on we need to look at it.”

The latest:#ArrestRandPaul trends after he walks out over impeachment question

And before trial impeachment proceedings began Thursday, Senate Majority Leader Mitch McConnell said, "We've been respectful of the chief justice's unique position in reading our questions, and I want to be able to continue to assure him that that level of consideration, for him, will continue."

Asked by reporters whether he thought McConnell's comments were directed at him, Paul laughed and said, "It did sound like code, didn't it?" before adding he didn't know what it meant. He added that he had no previous discussion with McConnell, a fellow Kentucky Republican, about his question.

Soon after reports spread of Paul walking out of the Senate, social media users began using the hashtag #ArrestRandPaul.

"Anybody who doesn’t speak out against Rand Paul outing the #Whistleblower in an interview today, may as well have done it themselves. Sometimes it’s what you fail to say that speaks louder than anything you’ve ever shouted from the rooftops. #ArrestRandPaul," one Twitter user wrote.

Another tweeted, "How do you violate senate rules and walk out to hold a press conference? #arrestrandpaul."

But in his press conference Thursday, Paul claimed he is the "biggest defender" of whistleblower statutes, or federal protections meant to prevent retaliation against informants who report misconduct. He pointed to his defense of Edward Snowden, who he called "the greatest whistleblower of all time."

Paul previously said he had "mixed feelings" about Snowden. In 2015, he said that while Snowden had shown "how our government lied to us," the former CIA employee should face some penalty for leaking classified National Security Agency materials.

More impeachment:Does McConnell's grin mean Trump's about to get good news?

Reporter Sarah Ladd contributed to this story.

Contact Ben Tobin at bjtobin@gannett.com and 502-582-4181 or follow on Twitter @TobinBen. Support strong local journalism by subscribing today: subscribe.courier-journal.com.