Trump is a disgusting fascist sociopath.
Liberals may not like Haley's policies, but at least she's mentally healthy.
So, yes, we'd rather see Haley get elected, than take any chance that a fascist sociopath gets elected.
We also do not want Trump to win the republican primary and get convicted - which seems to be almost certain. He would be barred from the Presidency, and it would cause a total mess with the Republican party and be very bad for the Democratic process.
We put Democracy and support for the Constitution as our top priority. Even if that means Haley becomes our next President.