Keith Whittington, William Nelson Cromwell Professor of Politics at Princeton University and a CSDP faculty associate, makes the case in The Washington Post that when the chief executive of the federal government incites an attack on the legislature, party differences should fall away.
[Trump's] offenses are of a 'political character,' of the sort that Supreme Court Justice Joseph Story said the impeachment power existed to address. They threaten the workings of American democracy. The president has, in the words of Alexander Hamilton, acted in grave 'violation of some public trust.'
.... After the Trump presidency, it will be a long and difficult task to restore balance and integrity to our constitutional system. That begins by emphatically reaffirming the most basic expectations of how a president should conduct himself. The power of impeachment is a tool for reestablishing constitutional principles that have come under assault. They are under assault now.