Democrats have successfully framed what is now the second-longest government shutdown in U.S. history around the issue of health care. Some three weeks in, it remains solid ground for the party, and it seems unlikely that they will budge.

Especially when considering another important reason why this will likely become the longest government shutdown ever and stretch on with no end in sight: President Donald Trump has usurped Congress’ power to appropriate and direct government spending and refuses to give it back. In doing so, Trump has broken any semblance of trust that Democrats may have that his end of any deal they strike will be honored after a bill is passed.

Since taking office, Trump has unilaterally impounded funds appropriated by Congress, frozen funds for scientific research, canceled grants for infrastructure largely in Democratic-run states, fired tens of thousands of government workers, shuttered whole agencies and attempted to shutter others. And he’s ramped up these practices, which range from provocative to outright illegal, during the shutdown.

Most ominously, Trump redirected funds within the Department of Defense from research and development to pay the salary of troops who would otherwise not be paid during the shutdown. This money was appropriated by Congress for one purpose and is now, at Trump’s unilateral direction, being used for another. That is neither legal, nor constitutional. The White House did not immediately respond to a request for comment.