Hitler's rise to power was through the use of scapegoating not only the Jews but also the Communist and Communist sympathizers, as seen through his speech on the November criminals.
I was wondering what sparked Hitler's vehement hatred of communists/communism. It seems that he blames them to be the cause of Germany's loss during WWI, but didn't Germany smuggle Lenin into Russia to destabilize the Czar's empire in order to win the War?
Yes there actually was. During the End of WW1 in 1918 there was a mutinity in the german Navy and because of that many cities in north germany actually "fell" to workers and soldiers who worked in councils (Räte in german) which were considered socialist or even communist if you want to say that. After WW1 you also had the Ebert-Groener Pact which was a secret treaty between Reichspräsident Ebert and leader of the Reichswehr Wilhelm Groener who assured Ebert the loyality of the Reichswehr incase there is a communist uprising which actually happened after WW1 in 1919 when communists led by the Spartakusbund wanted to take the power but failed due to the Reichswehr.
About the Lenin thing. You have to see that Lenin and his comradea wanted to make peace with Germany if they were at power. The social democratic Russia under Alexander Kerensky at that time did not want to make peace so it is logical for Germany to smuggle Lenin into Russia so that he could take the power and quickly make peace with Germany
There was a huge left-wing uprising in Germany in the 1918-19 period. As /u/Maxi_We says, there was a mutiny in the Germany Navy at Kiel - largely because they'd just been ordered to undertake what was basically a suicide mission. The news of this spread across Germany, leading to uprisings and seizures of power across Germany's major cities by left-wing groups. This was eventually crushed by the army and proto-Nazi Freikorps paramilitaries in January 1919. There was another uprising in Bavaria in April 1919 to attempt to break Bavaria away as an independent socialist republic, but this was also crushed by the army.
However, Nazi propaganda conflated the November Revolution's ending of the war with responsibility for Germany's defeat. By November 1918, Germany had realistically already lost the war. All the other central powers had agreed to armistices and it was suffering huge losses. It probably could have fought on for quite a bit longer - maybe even into early 1920 - but they were going to lose sooner or later. An often-repeated Nazi claim was that the Allied troops never even set foot on German soil during the war; this is true, but barely so; at some points along the front line Allied troops were days away from the German border - Petain believed the first French troops would cross into Alsace-Lorraine (at the time, part of Germany) as early as 13th November had the war continued.