From Gallup.com…
On average, Americans’ political party preferences in 2021 looked similar to prior years, with slightly more U.S. adults identifying as Democrats or leaning Democratic (46%) than identified as Republicans or leaned Republican (43%).
However, the general stability for the full-year average obscures a dramatic shift over the course of 2021, from a nine-percentage-point Democratic advantage in the first quarter to a rare five-point Republican edge in the fourth quarter.
These results are based on aggregated data from all U.S. Gallup telephone surveys in 2021, which included interviews with more than 12,000 randomly sampled U.S. adults.