What they meant is that, for the working class, both parties are effectively the same. They both represent the rich, albeit different subsections with slightly differing interests. Sometimes the rich assassinate the rich because some of the rich got in the way of other rich people. They have as much infighting as the left sometimes tbh. Regardless of that though they are both capitalist parties who primarily secure the interests of capitalists. They are the same in that neither of them give a shit about you other than what you can do for them. Which is to say, the illusion of political legitimacy and the wealth you create for them.