Memes

That's quite a cherry-picked quote, and to connect it to Bernie and AOC is to completely disregard the rest of the text.

Rosa draws a distinction between being a legislator in a parliament -- where you're able to battle the state within its own arena, and expose its contradictions -- and being an executive in a cabinet -- where your job is to manage crises and therefore hide contradictions.

But coming from a minister, social reforms can’t have the character of the proletarian class, but solely the character of the bourgeois class, for the minister, by the post he occupies, attaches himself to that class by all the functions of a bourgeois, militarist government. While in parliament, or on the municipal council, we obtain useful reforms by combating the bourgeois government, while occupying a ministerial post we arrive at the same reforms by supporting the bourgeois state.

She also explicitly endorses political engagement as a means of class struggle:

Personally, in this great gathering of the different socialist organizations in the free play of the daily political struggle, we don’t fear the least danger for the doctrine of Marx and the principles of democratic socialism, in as much as they have already taken root in France. There is no better school for socialist democracy than the great and living class struggle freed from abstract clichés. The materialist conception of history doesn’t allow us to believe in the development of a living popular movement begotten of abstract formulas; on the contrary, it’s on the material base of a great and strong class struggle, embracing all of the proletariat, that a clear conception of theory and principles will be erected.

And not for nothing, the Communist Manifesto does too:

In short, the Communists everywhere support every revolutionary movement against the existing social and political order of things.

In all these movements, they bring to the front, as the leading question in each, the property question, no matter what its degree of development at the time.

Finally, they labour everywhere for the union and agreement of the democratic parties of all countries.

The broader theme of Rosa's text is to not accidentally align yourself with liberals in a cross-class coalition by focusing only on the political question of the day. I think we're in danger of doing that with memes just as much as self-proclaimed socialist politicians are in danger of doing it by entering government.