In 1980 the Republican Party shifted. It had been the party of budget balance that sought to keep spending low so that the government could live within its means. It turned into the party of deficits that sought tax cuts at every opportunity with no thought whatsoever to whether the result would produce a government that lived within its means. Democrats, in response, shifted a bit toward fiscal responsibility, and became the party that sought to make sure that the government lived within its means but also had the means to live. Thus since 1980 the only way to vote for a sane, conservative budget policy was to vote for the liberal party.An article in Wikiepedia describes the other transformation of the Republican part that started under Nixon:
In American politics, the Southern strategy refers to a Republican Party method of winning Southern states in the latter decades of the 20th century and first decade of the 21st century by exploiting opposition among the once segregationist South to the cultural upheaval of New Left, Vietnam protests, the hippie culture, gun control, abortion and to desegregation and the Civil Rights Movement.What I find odd about American politics is that the Democratic Party of the 1850s was rural, conservative, anti-immigrant, generally pro-slavery, and very strong in the South. It was the Republican Party that was anti-slavery, more open to immigrants, more urban, and very strong in New England and the Midwest. That has switched 180 degrees over the next 120 years. Amazing!