Jo Swinson warned of the return of the “politics of the bully”, saying “Faragey, Trumpy, angry, arsey, shouty, slogans aren’t a solution to anything”.
Addressing the Lib Dem conference, Ms Swinson said a fresh vote on Brexit was part of her party’s approach to tackling populist politics.
Ms Swinson said: “Trump is a bully, a misogynist and a racist. He boasts about sexually assaulting women.
“He cruelly mocked a reporter for his disability. He has rolled back trans rights. And for someone who makes much of being straight-talking, he won’t call a Nazi a Nazi.
“Yet the Conservative Government thinks it is right to offer Trump the honour of a state visit to the UK. They are wrong.
“It is a sign of our weakness in a Brexit world.
“How easily will our values be cast aside in our desperation to sign trade deals to avoid economic catastrophe.”
At the party’s conference in Bournemouth, Ms Swinson said global politics seems broken “when calm heads and brave leaders are needed more than ever”.
She added: “A few years ago it would have seemed inconceivable that in such a crisis, China would be a voice of reason, and Russia more measured than America.
“The politics of the bully is back. Human rights are trampled. Climate change is denied. Hate and division are spread like poison into society.”
The Lib Dem deputy leader pointed to situations in North Korea, Turkey and Burma as evidence of global instability.
She also highlighted the regime in Venezuela, saying it “beggars belief that Jeremy Corbyn would rather defend a tenuous link to socialism than condemn these atrocities”.
Ms Swinson added: “We are absolutely right to fight for an exit from Brexit.
“Brexit will make it harder to follow our values, to protect human rights, to tackle climate change, to solve global problems.
“An exit from Brexit is necessary, but not sufficient.
“Because this culture clash continues, and the populists stoke this tension.
“They do it deliberately. They talk in simple soundbites that scapegoat different groups. It’s all someone else’s fault.
“As liberals we know this is nonsense. The Faragey, Trumpy, angry, arsey, shouty, slogans aren’t a solution to anything.
“But we do need to offer our own alternative solutions. We need to be much more radical, both in what we propose and in how we craft it.”