While it is true that leftists who pretend to be Christians don't evangelize in the proper sense of the term - i.e. they don't preach the gospel, they certainly do "evangelize" for socialism.
I'll just point out that someone who claims to be Christian and also claims not to evangelize is simply a liar.
I do believe that we are exhorted to spread the gospel. Some of us are better at it than others (I am sadly lacking)
As a Jew, I rather enjoy it... Because anybody who tries to sell me snake oil has better behave!