Question: when did the democrats and republicans switch roles?
Answer: After being the dominant party in U.S. politics from 1800 to 1829, the Democratic-Republicans split into two factions by 1828: the federalist National Republicans, and the Democrats. The Democrats and Whigs were evenly balanced in the 1830s and 1840s. However, by the 1850s, the Whigs disintegrated.