I'm looking for non-biased, accurate account of this. An acquaintance vehemently rejects the notion it happened, pointing to it as what the left wants us to believe basically. So looking for more fact than just opinion. Thanks!
It really matters what issue we're talking about. Applying labels like "conservative" or "liberal" in the abstract is really of little use, especially as the meaning of those terms shift over time.
However, when most people talk about the Democratic-Republican "switch", what they are typically referring to, is the way in which they switched positions on their policies on race in America. That is, since the time of Civil War and Reconstruction, the racist Southern white vote was an integral part of the Democratic constituency. These Southern Democrats would become increasingly independent from the rest of the Democratic party through the Administrations of FDR. The final straw for the Southern Democrats was when Kennedy, running in 1960, reversed the parties position on civil rights. In 1964 and 1968, both Goldwater and later more successfully Nixon ran campaigns appealing to the disaffected Southern white vote. Nixon's campaigns in 1968, 1972, were really when the Republican "Southern strategy" took hold, that is a strategy of keeping the South Republican through the politics of race.
Hi, fyi, you'll find more in this section of the FAQ