For the OP topic, rerun from another thread....
"Party switch" is an inaccurate term. It implies an instant stroke, like a politician changing his party registration, which takes about a minute.
More correctly these are "party shifts", evolving over time. Significantly at the turn of the (19th>20th) century, which was the big one. In the mid-19th century the Democratic Party had been the carrier of "states rights", decentralized government, and had reach nationwide before the Republicans were founded. It also danced around the issue of slavery, as did several other parties who ceased to exist including the Whigs, trying to have it both ways.
The Republican Party upon its founding in 1854 to its credit took a decisive stand to push Abolition when Democrats, Whigs, Know Nothings, Constitutional Unionists and other dying parties were basically either trying to placate individual states or ignore altogether an issue that was not going to be ignored and which was already being addressed in Europe and its remaining colonies.
Like any political party, once that ideal was realized the next goal of the party became self-perpetuation. By the end of the 1800s the Republicans were taking on the interests of the wealthy and the corporations, while the Democrats were absorbing the Populist Party and movement, which put working-class and eventually minorities and immigrants into its camp, producing the party class divisions that still resonate now. These were represented respectively by the two Williams, McKinley and Bryan.
World war brought rapid industrialization, a lot of immigrants from Catholic and Jewish Europe, and a lot of black migration to the North and Midwest. This of course fed the bigotry of the time --- it's no accident that the Klan was re-formed exactly in this period to capitalize on that paranoia --- and the Klan as already documented tried for a time to influence politics in both parties.
Once the Great Depression hit and FDR launched the New Deal the black vote went to Democrats, joining the Catholic, Jewish, immigrant and labor union constituencies, in the 1930s and has remained there ever since.
Meanwhile the same Democratic Party was playing a bipolar game with these minorities on one hand coexisting in the same party with staunch white conservatism in the South that opposed those same constituencies (as did the Klan itself), railing against "Northern Liberals" and "civil rights" and leading to several schisms (Thurmond 1948; Wallace 1964/68/72).
The Democrats were, again, spinelessly trying to have it both ways, Liberal here, Conservative there, knowing the white South in its hyperconservatism considered association with the Republican Party unthinkable. As long as those hyperconservatives were in the same party they were in a position to block progress, which they did. FDR chipped away at it in 1936 when at the height of his power he got the party convention nomination rules changed to a simple majority (it had been 2/3) so that the Southern bloc could not block Liberals it didn't like (as it had in 1924). The 1948 convention chipped away at it again when the South heard too much talk about "civil rights" from Truman and the young mayor of Minneapolis Hubert Humphrey, and walked out to run their own candidates. Even got Truman's name wiped off the ballot in Alabama.
Thurmond then endorsed Eisenhower in the next election, and in retaliation was kicked off the Democratic ballot and ran as a write-in (which he won). Twelve years later George Wallace tendered an offer to Barry Goldwater to switch parties and run with Goldwater as his running mate. Goldwater declined and Wallace didn't make the switch but clearly the idea of "Republican" was becoming thinkable.
Clearly there were opposing dynamics and something had to give. Enter the Civil Rights Act of 1964, drafted by Kennedy five months before his death, pushed by LBJ, shepherded through Congress by Democrats Humphrey and majority leader Mike Mansfield and opposed by Democrats Thurmond, Byrd, Eastland (MS), Russell (GA) and the South in general. When that Southern contingent lost that battle, Thurmond finally acknowledged that it was after all "thinkable" to join the party that more represented his conservatism and switched to Republican, becoming the first prominent white Southern politician to do that, ninety-nine years after the Civil War ended. The divorce was, finally, final. He would be followed by other traditional Democrats including the Senator who lauded him at his 100th birthday, Trent Lott.
That's what the "party shifts" were. The former (around 1900) was a shift in the two parties' constituency; the latter (1964- ) was a shift OF a constituency to the other party. Bottom line--- both voters, and politicians, join (or switch) political parties for many more reasons than that they agree with its presumed ideology, two of which are practicality and simple tradition.
"Party switch" is an inaccurate term. It implies an instant stroke, like a politician changing his party registration, which takes about a minute.
More correctly these are "party shifts", evolving over time. Significantly at the turn of the (19th>20th) century, which was the big one. In the mid-19th century the Democratic Party had been the carrier of "states rights", decentralized government, and had reach nationwide before the Republicans were founded. It also danced around the issue of slavery, as did several other parties who ceased to exist including the Whigs, trying to have it both ways.
The Republican Party upon its founding in 1854 to its credit took a decisive stand to push Abolition when Democrats, Whigs, Know Nothings, Constitutional Unionists and other dying parties were basically either trying to placate individual states or ignore altogether an issue that was not going to be ignored and which was already being addressed in Europe and its remaining colonies.
Like any political party, once that ideal was realized the next goal of the party became self-perpetuation. By the end of the 1800s the Republicans were taking on the interests of the wealthy and the corporations, while the Democrats were absorbing the Populist Party and movement, which put working-class and eventually minorities and immigrants into its camp, producing the party class divisions that still resonate now. These were represented respectively by the two Williams, McKinley and Bryan.
World war brought rapid industrialization, a lot of immigrants from Catholic and Jewish Europe, and a lot of black migration to the North and Midwest. This of course fed the bigotry of the time --- it's no accident that the Klan was re-formed exactly in this period to capitalize on that paranoia --- and the Klan as already documented tried for a time to influence politics in both parties.
Once the Great Depression hit and FDR launched the New Deal the black vote went to Democrats, joining the Catholic, Jewish, immigrant and labor union constituencies, in the 1930s and has remained there ever since.
Meanwhile the same Democratic Party was playing a bipolar game with these minorities on one hand coexisting in the same party with staunch white conservatism in the South that opposed those same constituencies (as did the Klan itself), railing against "Northern Liberals" and "civil rights" and leading to several schisms (Thurmond 1948; Wallace 1964/68/72).
The Democrats were, again, spinelessly trying to have it both ways, Liberal here, Conservative there, knowing the white South in its hyperconservatism considered association with the Republican Party unthinkable. As long as those hyperconservatives were in the same party they were in a position to block progress, which they did. FDR chipped away at it in 1936 when at the height of his power he got the party convention nomination rules changed to a simple majority (it had been 2/3) so that the Southern bloc could not block Liberals it didn't like (as it had in 1924). The 1948 convention chipped away at it again when the South heard too much talk about "civil rights" from Truman and the young mayor of Minneapolis Hubert Humphrey, and walked out to run their own candidates. Even got Truman's name wiped off the ballot in Alabama.
Thurmond then endorsed Eisenhower in the next election, and in retaliation was kicked off the Democratic ballot and ran as a write-in (which he won). Twelve years later George Wallace tendered an offer to Barry Goldwater to switch parties and run with Goldwater as his running mate. Goldwater declined and Wallace didn't make the switch but clearly the idea of "Republican" was becoming thinkable.
Clearly there were opposing dynamics and something had to give. Enter the Civil Rights Act of 1964, drafted by Kennedy five months before his death, pushed by LBJ, shepherded through Congress by Democrats Humphrey and majority leader Mike Mansfield and opposed by Democrats Thurmond, Byrd, Eastland (MS), Russell (GA) and the South in general. When that Southern contingent lost that battle, Thurmond finally acknowledged that it was after all "thinkable" to join the party that more represented his conservatism and switched to Republican, becoming the first prominent white Southern politician to do that, ninety-nine years after the Civil War ended. The divorce was, finally, final. He would be followed by other traditional Democrats including the Senator who lauded him at his 100th birthday, Trent Lott.
That's what the "party shifts" were. The former (around 1900) was a shift in the two parties' constituency; the latter (1964- ) was a shift OF a constituency to the other party. Bottom line--- both voters, and politicians, join (or switch) political parties for many more reasons than that they agree with its presumed ideology, two of which are practicality and simple tradition.