U.S. Political Party Preferences Shifted Greatly During 2021

 https://news.gallup.com/poll/388781/political-party-preferences-shifted-greatly-during-2021.aspx

Bottom Line

The year 2021 was an eventful one in politics, after a similarly eventful 2020 that also saw major shifts in party preferences. In early 2021, Democratic strength reached levels not seen in nearly a decade. By the third quarter, those Democratic gains evaporated as Biden's job approval declined. The political winds continued to become more favorable to Republicans in the fourth quarter, giving the GOP an advantage over Democrats larger than any they had achieved in more than 25 years.

The final monthly survey of 2021 showed the parties at roughly even strength, although that still represents a departure from the historical norm of the Democratic Party's having at least a slight advantage in party affiliation.