Until the end of the 19^th Century the Republicans and Democrats fought “base elections,” drawing sharp, detailed distinctions between each other and focusing their efforts on building grassroots turnout organizations, rather than persuasion of the undecided. The GOP was formed in the North to fight slavery and polygamy (in Utah). They were associated with Lincoln and victory in the war between the states. They were generally for an activist federal government that subsidized railroads and adjacent economic development. They  supported the top-down nation-building effort in the South after the war called Reconstruction. The GOP tended to support government restrictions like the prohibition of alcohol.

Democrats cobbled a disparate coalition of white segregationists in the South, often Catholic immigrants in northern cities, German Americans in the rural Midwest, and agriculture and mining interests in the western U.S. This unlikely coalition united around their belief that the federal government should have a limited role in their lives. The marked differences within this coalition prompted Will Rogers to once quip “I am not a member of any organized political party, I’m a Democrat.” Republicans summed up this odd coalition by attacking Democrats as the party of “Rum, Romanism, and Rebellion.”

The influence of progressive ideas supporting expansion of government infected both political parties and greatly reduced these partisan differences at the beginning of the 20^th Century. After WWII the “bipartisan consensus” was formed, supporting internationalism and UN institutions abroad and the acceptance of past and future New Deal-type programs at home. From 1912 till the election of 1964 the reduction of distinct differences between the parties moved political communications to be based more on contrived differences or the personalities of the candidates. Positive image creation and sloganeering was a high priority. Vicious personal attacks on opponents usually launched by surrogates were often a part of the playbook.

This trend began to be reversed in the 60s. Large, organized blocks of ideologically-driven voters emerged on both the left and the right. They were aided by computerized mailing lists targeting voters by “hot button” issue, interest group membership, or past campaign donations. Candidates carefully appealed to them in primaries. But generally these candidates still “moved to the middle” for general elections, reverting to the soundbites of the  homogenized, consultant-led, poll-driven campaign.

The 2000 “hanging chad” election, the return of labor to grassroots political activism, the Iraq War, and most importantly grassroots communications and organizing via the internet restored a strongly partisan dynamic in American elections, moving the Democrats left and the GOP right. A further evolution was the GOP’s embrace of America First thinking on trade, immigration, and overseas wars through the successful candidacies of Donald Trump. Oddly, the Democrats have moved in lockstep to accept the  establishment positions on these three issues, as well as on forced vaccinations, racial preferences, election integrity questions, abortion, and gender issues. The GOP has remained constant on guns, life, taxes, and in their extreme skepticism of the public school system.