To rule any way other than how Leon has would be to allow the president to punish law firms for their protected speech in favor of causes or issues Trump doesn't support. Dating back to John Adams, lawyers in the United States have prided themselves on their impartial representation of even the most controversial clients, and that should continue because it's crucial to the way the American justice system functions.
It's appalling that after years of lawfare against Trump and anyone in the legal profession willing to stand with him, activist judges are now scrambling to shield liberal law firms from the consequences of abandoning professional impartiality. Liberal lawyers and their firms now know what it's like to be a conservative and face scorn — and worse — for representing causes the government doesn't back.