The Communist Party (KPD) did not help Hitler to power. But the conservative forces gave him considerable support at the time because they feared that the communists could win the election and form a government. What ultimately enabled Hitler to seize power was the Reichstag fire decree following the fire in the Reichstag in 1933. Hitler used this decree, which was only possible with the support of the conservatives, to brutally persecute the Communist Party, crush all civil and political resistance and ultimately install himself as a dictator with absolute power.
The Communist Party (KPD) did not help Hitler to power.
Oh, it certainly did. The KPD was headed by Ernst Thallman, a dedicated bootlicking Stalinist, and was quite fine with working with the Nazis in the hope of crushing their 'liberal' enemies and ushering in fascism to trigger a 'revolutionary crisis' that they could use to wipe out the Nazis in turn. Turns out, helping shitheads get into power doesn't cause a magic left-wing reaction.
That being said, the conservatives are far, FAR more culpable.
I was not aware that the KPD had ever cooperated with the Nazis. I'll have to read up on that.
Still, I think it's a bit far-fetched to see the KPD as Hitler's enabler. After all, the Communists were one of the Nazis' main enemies and put up considerable resistance until the end (as did the SPD, which exists again today as a (somewhat) social democratic party under the same name after being banned following Hitler's seizure of power).