I think they are sincere and mean well. But liberalism today has a narrative that portrays liberalism as the force of progress out of darkness into light and love.
Psychology does well to warn of the phenomenon, although hardly specific to "liberals". To love something, even unconditionally or as a state of being requires first and foremost healthy boundaries. Love starts with a "no" even before granting a yes.
A loving parent demands a responsibility in exchange for privilege even in the face of a well behaved child. Hate is not breed in the tyranny of not being responsive enough to need, nor lacking empathy, nor even face of a peer being narrow sighted as to their worth. Hate always breed from resentment. Attention to need, empathy and recognition are all great as expression of genuine love, require first a firm boundary. This is because trust.
No person is empower when no boundary is set which respect their own. If their happiness is your happiness. You have perpetrated a violation and laid only the seeds for resentment both for yourself and those who you attest with your unrequited psudeo-love.
Love. Must begin by defining your limit. Your standard. You're condition. Your love, like with your child may well be unconditional in nature, but love's expression can not be without consent. Without trust. Trust begins by recognizing within us is a little tyrant too happy to respond to resentment with unbridle hate and psudeo-love with undefined conditions always leads to more resentment.
"Liberals" like so many are by and large resentful people even if so only specific in the domain to politics. The sincere gestures and well meaningless overshadowed as they find themselves unable to separate disagreement from personal choice. Their progress mostly their ego's identified objectives being met without confirmation by genuine effect nor confirmation by the reciver.
Hate, leads way to more resentment. Hatred is no doubt a Basic Human Right, but justifying that hate as necessary to love only just a different way to fail to set your own boundaries. The boundryless will exist and attempt to sow their resentfulness to justify their unfulfilled desires every hungry for more.
But, Be fulfilled. Glad to tell your love ones "no" and it is easy to love. They're disagreement no more angering them watching them destroy themselves by their own hate. No doubt their jackel ways will invite times of tough love, but all and all hate holds very little value except as a warning to exmine ones own resentments.