President Donald Trump's personal lawyer, Rudy Giuliani, remains one of the most prominent figures of the ongoing impeachment inquiry against his client, but it's not because of the validity of his defense.

In fact, evidence is beginning to show that Giuliani is far from blameless. He's previously admitted to urging Ukrainian officials to open an investigation into Trump's possible 2020 opponent, former Vice President Joe Biden. Giuliani contends that he did so at the behest of the State Department, leading some to question the legality of the President's personal lawyer working with the State Department to open up investigations that personally benefit the President instead of the country.

Now, Giuliani seems determined to commit obstruction of justice as well. His lawyer, Jon Sale, told the select committees overseeing Trump's impeachment inquiry that Giuliani wouldn't comply with their "overbroad, unduly burdensome" subpoena for documents relating to his dealings with Ukrainian officials.

When asked about his refusal to comply with the subpoena, Giuliani said, “If [the Committees overseeing impeachment] enforce it, then we will see what happens." The challenge from Giuliani to the Committees could backfire if they vote to hold him in contempt.

After sending the letter to lawmakers, Giuliani's lawyer stepped down, which Giuliani says is fine, because he doesn't need a lawyer "at this time."

People don't seem to believe this strategy is going to pay off for Giuliani.

In fact, the Committees overseeing the impeachment inquiry could choose to hold Giuliani in contempt, and possibly even arrest him. An 1821 Supreme Court case found that Congress has "inherent authority" to arrest witnesses who don't comply with subpoenas, but the right hasn't been exercised since 1927, and experts don't expect it to make a comeback.

But given the numerous times Trump officials have defied subpoenas with no consequences, Americans across the country want Congress to toughen up—calling on the Sergeant at Arms to arrest Giuliani at the Yankees game he said he'd be attending instead of relinquishing the documents.

It's unclear how lawmakers intend to enforce the subpoena, now that Giuliani's made it clear he has no intentions to comply. Arrest would be a nuclear option.