I've seen what happens when Liberals go toe to toe with the right in a debate. When they face off with anyone from mainstream conservatives to the alt-right to full-on fascists it nearly always ends in embarrassment.
Why should we socialists feel embarrassed by the antics of liberals that get in over their heads?
Because, for better or worse we get associated with them, especially when it comes to dealing with the reactionary right.
I've seen enough of liberals tying themselves up in knots, stumbling over their words, saying things they didn't mean to say (or at least saying things they didn't like the sound of when they came out). And the 'logical', 'strong', 'intelligent' right winger launches blow after blow with a smile on their face as, to their delight, everything they expected to happen when they got into a debate with a liberal does, in fact, happen:
The average liberal's world view turns out to be mere fluff. Full of inconsistencies, based on assumptions about expected norms of 'right' and 'wrong' and belief that social pressure can continue to enforce these, lacking any background study and so failing to understand the philosophical points at stake in each round they begin to look for a way out, or worse they begin seeking compromise or approval.
Why does this happen?
Because the right wing arguments are perfectly suited to their natural environment, capitalism. They often make fairly good sense in a world where everyone is an individual, responsible for whether they 'win' or 'lose'. In this world, plainly, everyone, is already getting what they deserve, because they deserve whatever they managed to grab during this short life and 'losers' deserve their lot too.
Liberals enter into the debate with the same basic individualist assumptions, even if they've got icing on top of theirs, it's the same cake.
If you accept a world where capitalists have freedom to run a private business you're going to struggle to show how people who don't own that business get a say in how it operates. If you accept a world where everyone has to compete to survive you will find it quite a challenge to justify inserting in special clauses that limit the way this operates to ensure that people who are ostensibly 'losing' don't get such a rough deal.
It gets worse.
I have literally heard liberals argue that all migration is good on the basis that "if we don't let migrants in who's going to do all the shit jobs we don't want to do?" At which point, presumably the fascist who hadn't considered the benefits of importing a class of slaves to clean their toilets begins to reconsider their position...
Leave it to the left. Please.
Let us show how the right are acting as lap dogs for the capitalist class who own our homes and our workplaces and run our government, require us to feel atomised and isolated, blaming ourselves for anything that goes wrong and/or being willing to step on people's heads to stay just above them on the ladder while the capitalists are ten floors up at the party already, egging us on and laughing. Listen then, to how our message - that if we all learn to have a bit of solidarity with the rest of our class and start working together against these greedy bastards we can win - starts to sound a bit more appealing... no? Where are the right wing going to go now they've been exposed?
Let us show that private businesses are based on systematic theft and that the socialist alternative where industry is run democratically by the class of people who do the work, not unaccountable bosses is the only solid ground for demanding equality for all. Not begging the boss to be nicer, or kissing the bosses ass as the right advocate.
Let us show that people deserve the right to settle where ever they want but also deserve the right not to be bombed or starved out of their homes too. That bosses do try to use open borders to bring in cheap labour but that, obviously, isn't the fault of the workers than come to take up the offer. That the value of all working class people, immigrant or not isn't found in whether we can be of useful service to the boss or please the ruling class by adhering to their bourgeois morality or nationalism, but in our human dignity.