What is the use of the particle "は" in this sentence?


I'm currently translating the lyrics of "Realize" by Konomi Suzuki. And the
one thing that made me confused was the use of the particle "は" in this
sentence of the lyrics. 歩き続けた今を消しては 見ない様に塞いだ過去 Is the "は" working as a topic
marker particle making the sentence after the particle the predicate or is it
indicating contrast between the two sentences? I need some help.

