Trial of former Trump campaign adviser Roger Stone off to a strange start Stone pleaded not guilty to the seven counts brought by the special counsel.

Day one in the long-anticipated trial of Roger Stone, a veteran Republican operative and onetime campaign adviser to President Donald Trump, limped forward Tuesday morning amid a series of setbacks that slowed the jury selection process.

There were squabbles in the hallway between people with tangential connections to the case. A prospective juror had to be carried out on a stretcher. And Stone himself appeared to be felled by some mysterious malady, which he later told the judge was food poisoning.

The criminal case of the longtime political showman, known for his unpredictable antics, launched on a trajectory Tuesday that was consistent with the personality of the man in the defendant's chair. While the theatrics are sure to dominate outside of his two-week trial, the charges confronting Stone are serious and could bring jail time.

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In January, former special counsel Robert Mueller indicted Stone on five counts of lying to Congress, witness tampering and obstruction of justice in connection to Mueller's probe into possible coordination between the Trump campaign and Russian meddling in the 2016 U.S. presidential election. Stone has pleaded not guilty to all seven counts.

Details from Stone's trial could fill several important gaps in the public's understanding of the special counsel's investigation, which lasted nearly two years and culminated in a comprehensive 448-page report. Several redactions in the Mueller report, related to ongoing investigations, appear connected to Stone's case.

The special counsel ultimately found that while the Trump campaign “expected it would benefit electorally from information stolen and released through Russian efforts, the investigation did not establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities,” according to the special counsel's report.

With jury selection underway on Tuesday -- and continuing into the afternoon without Stone, who was excused from court due to his illness -- Jackson said lawyers for the government and defense counsel for Stone should be prepared to give opening statements as early as Wednesday, though it was not clear how the delays caused by Stone's illness could impact that timeline.

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Stone -- a friend of Trump's since the late 1970s, who has taken credit for persuading the president to get into politics -- served as an adviser to Trump's presidential campaign but left amid controversy in 2015.

In the indictment, the special counsel's office described Stone as a conduit between the Trump campaign and Wikileaks, which disseminated internal Democratic National Committee emails in the summer of 2016.

The bulk of the charges Stone faces reflect allegations that he lied to Congress regarding his communications with associates about WikiLeaks. He also stands accused of witness tampering as part of an effort to keep humorist and radio show host Randy Credico from contradicting his testimony before the House Intelligence Committee in September 2017.

The 10 months since his arrest have been marked -- in large part -- by Stone's trademark political theatrics. Jackson has gradually imposed more stringent gag orders on Stone, who, at one point, targeted the judge in a social media post. Ahead of his trial, Stone is prohibited from speaking publicly about the case and is barred from using any form of social media.

Michael Ares/The Palm Beach Post/ZUMA Wire via Newscom, FILE

In a preemptive warning to Stone and his defense team during Monday's pretrial conference, Jackson said the court intends "to follow the rules" at his trial.

Stone said he expects to be "fully vindicated."

If the jury finds Stone guilty on all counts, he could face up to 50 years in prison.

Asked by ABC News on Monday for comment on his upcoming trial, Stone replied, “No comment at all, thank you," before getting into a waiting SUV with his wife, Nydia Stone, and daughter, Adria Stone.

An attorney for Stone also declined to comment on the trial when asked by ABC News on Monday.

Editor’s Note: This story previously misidentified the statutory maximum for Roger Stone’s crimes as 20 years in prison. The actual maximum is 50 years in prison. We regret the error.