The Senate affirmed the constitutional basis of former President Donald Trump’s second impeachment trial, clearing the way for arguments to begin on whether he incited an insurrection by inflaming the mob that stormed the U.S. Capitol last month. After four hours of arguments from House impeachment managers and Trump’s defense team, the Senate voted 56-44 to proceed with the trial, rejecting the former president’s contention that it is unconstitutional to try an official who is no longer in office. Six Republicans joined with Democrats in voting to continue to the trial: Lisa Murkowski of Alaska, Bill Cassidy of Louisiana, Susan Collins of Maine, Mitt Romney of Utah, Ben Sasse of Nebraska and Pat Toomey of Pennsylvania. Still, that is far short of the 67 votes that would be required for a conviction. Opening arguments are set to begin at noon on Wednesday. Trump was impeached by the House on a single article accusing him of incitement of insurrection for stoking the anger of his supporters, leading to the mob storming the U.S. Capitol on Jan. 6 as Congress was certifying the Electoral College count that delivered the presidency to Joe Biden. Trump’s lawyers had argued that his impeachment by the House was a politically motivated attempt to remove him as a challenger to Democratic power rather than a constitutional remedy for any wrongdoing. “We are really here because the majority of the House of Representatives do not want to face Donald Trump as a political rival,” attorney Bruce Castor said as the former president’s defense team argued that the Senate’s impeachment trial is unconstitutional. Another Trump lawyer, David Schoen, said that Democrats have an “insatiable lust for impeachment.” During his presentation, Schoen played a video showing a procession of Democrats in Congress demanding Trump’s impeachment starting as early as 2017. Representative Jamie Raskin of Maryland, the lead House impeachment manager, argued that there is no “January exception” to holding a president accountable for his actions just before leaving office.