IDK why, but here in Denmark it's not the case. Our most leftist party in parliament "Enhedslisten" (Unity List), that was based on several minor dissolved extreme left parties, including the communist party that collapsed when Russia couldn't afford to continue to support it.

That party which wanted Denmark out of NATO, is now a very vocal party against Russia, and a very strong supporter of Ukraine. Immediately after the Russian invasion of Ukraine, they even changed the policy against NATO to remain until a suitable alternative exist.

There are no parties either right or left wing out of 14 parties in parlament that in any way support Russia, or argues that Ukraine should be the one to seek peace with Russia. (Russian talking point)

The ones who were taken for a ride seems to me to be mostly American Republicans, who cheer Trump when he argues about how amazing Russia would be to have as a friend because they are stronk. And the crowd cheered when Trump asked Russia to interfere in the US election. Trump worked against Ukraine from day one as president, undermining US support.

There have been cases on the left too, but they are by far minor players and isolated cases, compared to how it entered into the Republican party and spread widely.