Hunter Biden made an in-court appearance on Tuesday in order to plead "not guilty" to a series of gun charges that were part of a plea deal that fell through this past summer.

The "not guilty" plea sets up a court battle that will take place while his father, President Joe Biden, will be fighting for re-election. Biden's lawyers are arguing that this legal battle is all a constitutional violation.

His lawyer Abbe Lowell said in court he plans to file a motion to dismiss the charges, challenging their constitutionality.

“Mr. Biden pleads not guilty to the three counts that have been brought against him,” Lowell said to the judge.

Hunter Biden has acknowledged struggling with an addiction to crack cocaine during that period in 2018, but his lawyers have said he didn’t break the law. Gun charges like these are rare, and an appeals court has found the ban on drug users having guns violates the Second Amendment under new Supreme Court standards.

The judge noted on Tuesday that Hunter Biden had tested negative for drugs in a recent drug test. 

The charges were originally going to be addressed in a plea deal that Biden had taken over the summer, but a judge rejected that plea deal, infuriating the defense team and setting up the current legal battle. Biden then requested permission to appear in court via video conference rather than in person. That, too, was rejected.

Biden's plea in court today will set up a legal fight that will take place while his father is running for re-election. The president's team has attempted to maintain its distance from the younger Biden's legal drama and congressional investigations. However, Republicans in Congress have been working to tie the president to his son's business deals. There have also been several questions raised at the plea deal that collapsed this summer, with many Republicans calling it weak and accusing the Biden administration of a "two-tiered justice system."