More than 1 million voters across 43 states have switched to the Republican Party over the last year, according to voter registration data analyzed by The Associated Press. The previously unreported number reflects a phenomenon that is playing out in virtually every region of the country — Democratic and Republican states along with cities and small towns — in the period since President Joe Biden replaced former President Donald Trump.

But nowhere is the shift more pronounced — and dangerous for Democrats — than in the suburbs, where well-educated swing voters who turned against Trump’s Republican Party in recent years appear to be swinging back. Over the last year, far more people are switching to the GOP across suburban counties from Denver to Atlanta and Pittsburgh and Cleveland. Republicans also gained ground in counties around medium-size cities such as Harrisburg, Pennsylvania; Raleigh, North Carolina; Augusta, Georgia; and Des Moines, Iowa.

Ben Smith, who lives in suburban Larimer County, Colorado, north of Denver, said he reluctantly registered as a Republican earlier in the year after becoming increasingly concerned about the Democrats’ support in some localities for mandatory COVID-19 vaccines, the party’s inability to quell violent crime and its frequent focus on racial justice.