Over the past decade, the Republican Party has undergone a dramatic transformation. Once known as the party of Abraham Lincoln and conservatism, it has seemingly morphed into the party of Donald Trump. This three-part series traces the evolution of the Grand Old Party (GOP) from 2015 and the candidacy of Donald Trump, his presidency, and finally, its implications for the party's future and the future of our democracy with Trump as the presumptive presidential candidate in 2024.