Editor’s Note: In this weekly column “Cross Exam,” Elie Honig, a CNN legal analyst and former federal and state prosecutor, gives his take on the latest legal news. Post your questions below. The views expressed in this commentary are his own. View more opinion on CNN. Watch Honig answer readers’ questions on “CNN Newsroom with Ana Cabrera” at 5:40 p.m. ET Sundays.

CNN  — 

After years of political wrangling and multi-front litigation, the Supreme Court will hear oral arguments Tuesday on the battle over President Donald Trump’s tax returns. The stakes are enormous. The court will decide by the end of its current term not only whether Trump’s tax returns ever see light of day, but also whether the President stands so far above the law that he cannot meaningfully be held accountable to other branches of government and the American public.

Elie Honig

The dispute over Trump’s tax returns has been politically heated but, legally, this should be an easy call for the court. Trump has fought to the bitter end, though ultimately the law should give him no refuge: the tax returns must go to Congress, and even as a sitting president, he cannot be immune from investigation by prosecutors.

The Supreme Court will actually hear three separate cases that it has consolidated for argument (using its new remote live-feed). In two of those cases, Democratic-controlled House committees subpoenaed Trump’s private banks for his financial records, including tax returns. And, in the third case, the New York County (Manhattan) District Attorney served a grand jury subpoena on one of Trump’s financial firms, as part of a criminal investigation into hush-money payments to two women with whom Trump allegedly had affairs (Trump denies the affairs). Though not a party to the subpoenas, Trump nonetheless jumped in and tried to block them.

Legally, this shouldn’t be particularly close or difficult. Exhibit A: In total, six different federal courts – three district courts and three courts of appeals panels – have heard these cases, and all six have ruled against Trump. It’s no fluke that Trump has a batting average of exactly .000 thus far in trying to block disclosure of his tax returns, and it would take a stunning reversal by the Supreme Court – essentially deciding that all six lower courts got it wrong – to save Trump’s cause now.

The primary issue in the cases involving House subpoenas is whether Congress had some legitimate legislative purpose for requesting the tax returns. Courts traditionally interpret this requirement broadly in favor of Congress, sensibly deferring to the legislative branch to decide its own legislative purposes in all but the most egregious cases. In both cases involving House subpoenas, the district courts and courts of appeals ruled that the House was well within its authority to seek Trump’s financial information, which could inform various legitimate legislative purposes. The Supreme Court would have to twist itself into a legal pretzel – essentially substituting its own legislative preferences for those of Congress – to reach a contrary conclusion now.

The Supreme Court recently threw an unexpected twist into the proceedings when it requested additional briefings on whether the case presents a “political question unfit for judicial resolution.” This could signal that the court is looking for some off-ramp, some way to rule, in essence, that it cannot rule. However, federal courts – including all of the lower courts in the Trump tax returns cases – routinely rule on the enforceability of congressional subpoenas. It would be an unconscionable cop-out by the court to suddenly change this precedent, essentially rendering the Judicial Branch an ineffectual bystander to core constitutional disputes between Congress and the Executive Branch.

If Trump’s argument against the congressional subpoenas is weak, then his effort to block a prosecutorial subpoena from the Manhattan DA is downright monarchical. One district court judge rightly lambasted Trump’s argument that he is immune from even being investigated while in office as “repugnant to the nation’s governmental structure and constitutional values.” Indeed, Trump’s argument, if accepted, would place the President beyond almost any accountability, and would render law enforcement unable to even gather facts relating to potential crimes committed by the President while in office. Under Trump’s reading, if he in fact shot somebody on Fifth Avenue (to use his own hypothetical), the police could not even investigate the crime scene as long as he held the presidency.