Last week, Donald Trump's lawyers formally accepted service of the Jan. 6 committee's subpoena demanding documents by Friday and the former president's testimony 10 days later, setting the stage for a historic legal battle pitting the executive branch against the legislative branch.
That is as far as the fight will go, I'd wager. Each side has good reason not to test its luck by filing suit.
Of course, a fight would not be in question if the former president chose to comply with Congress' legal demands. There are reports that Trump, supremely confident of his ability to dominate any public setting, is actually eager to testify.