The political success of the GOP the last half-century in the white South is primarily due to white southerners liking conservative positions on taxes, moral values and national security. Southern Democratic politicians of the Jim Crow era, following the Civil War, mostly took conservative stances on all these issues. The peculiar thing about Jim Crow politics is that white southerners with conservative views on taxes, moral values and national security would vote for Democratic presidential candidates who didn't share their views. They voted that way as part of a grand strategy for maintaining white supremacy in the South.
That strategy worked for a long time. Democratic politicians like Woodrow Wilson and Franklin Roosevelt loyally upheld white supremacy. The strategy began to fall apart with Harry Truman allowing equal rights in the military by combining both Black and white units. Lyndon Johnson's actions regarding civil rights further eroded the grand strategy. White southerners took their conservative views on taxes, moral values and national security to the Republican Party where such views were soon placed at the spear point of their party's political views. These primary views of the Republican Party mask the major intent of the modern Republican Party, which is racism in its barest form. The citizens of the Republican Party in Lincoln's era would not recognize the GOP as of today. More than likely, the vast majority would be ashamed.
Should it really matter if you're Republican or Democrat? Does it matter if you're from the South or the North when life-threatening issues come about? Threatening issues like COVID-19 or for example, caring if the nurse or physician attending to your health problems may be either Black or white? If in the military and you are ordered to take an enemy's hilltop position, should you ask those to follow you by first asking are you a Democrat, Republican, Southerner or Northerner? I would hope the answer to any of the above challenges would be a resolute "no it doesn't matter."