"Trump's taxes have long been the Democrats' 'white whale,'" his lawyers said earlier this week. "No one believes that Chairman Neal requested President Trump's tax returns so he can study legislation about IRS audits. No one. Chairman Neal admits that this justification was a mere litigation strategy. His fellow Committee-Members don't buy it either," they continued. "Anyone who's paid even minimal attention to American politics understands what's happening here: President Trump did not voluntarily disclose his tax returns during the campaign, his political opponents assume the information would damage him, and so his opponents want to force the disclosure."
Trump has always been very secretive about his tax information (whether that's because he has something to hide is just speculation, as it has never been confirmed nor denied) especially during his time in office. He even broke with decades of tradition by not voluntarily releasing his tax returns when he was running for president, and threatened to sue absolutely anyone who tried to access them during his presidency.
The Ways and Means committee asked for Trump’s tax returns stating it was "concerned about whether the IRS had the resources and safeguards to audit the returns of Mr. Trump and similar future presidents effectively." It also wanted to see if the audits were performed properly and independently, and so invoked a federal law requiring the Treasury Department and IRS to provide any individual’s tax returns when demanded by any of the congressional tax code-writing committees, no questions asked.
Trump’s lawyers argued that this federal law is unconstitutional (one of their favorite lines when they don’t have much else of a defense) because the Constitution does not allow Congress to go after information with such open-ended authority. They also think that because the request first came about while Trump was in office, that he should have the same legal protection as he did at the time (really grasping at straws now!). "The committee's request is effectively a request to a sitting president: it was issued while President Trump was in office, was continuously pursued, and has always been tied to his status as president." This was quickly shot down by the committee though, who said that privilege only applies to a sitting president’s records in response to a subpoena. By contrast, this request was authorized by a specific federal law, which unfortunately for Trump as a now-former-president means he doesn’t have the same protection (nice try though!).
In response to all of this, lawyers for the House have said that the committee’s need for the tax returns is genuine, and that anyway federal courts do not have the power to judge the motives of Congress to say whether they are constitutional or not. The Ways and Means Committee first asked for the returns in 2019, but the Trump administration Treasury Department refused and the Justice Department's Office of Legal Counsel backed up the decision, concluding that the request was invalid – in line with the administration’s interpretation of the Constitution that the President cannot be investigated for anything at all!
The committee sued the Treasury Department for not handing over the returns during his presidency, however under the Biden administration the Treasury Department and IRS have agreed to provide the returns prompting the committee to drop the lawsuit. A new Justice Department legal analysis also said that the previous decision failed to give a coordinate branch of government the "respect and deference" it was due. All will hopefully soon be resolved, as US District Court Judge Trevor McFadden for the District of Columbia has scheduled a hearing on the dispute November 16th.