WRONG.
The first rule of power for any actual Leftist is to organize the forces needed to seize power and enact Leftist policies. It is NOT to ride off the backs of Right-bending "centrist" parties. "Building a better future" by allowing your favored "opposition" to use your fear of the Right to gloss over their own conservative foundation is not even close to "leftist". Neither, by the way, is abetting genocide.