For the last 150 years, we have had just 2 viable national parties. Since the collapse of the Whig Party in 1854, we have had just the Republican and Democrat parties that have been able to sustain themselves as viable national parties. While other parties have come along with some national support they have not been able to sustain viability beyond one election cycle. The Republican Party is now in a situation similar to what the Whig Party faced in the 1850s. The Whig Pary was fragmented around the slavery issue as the current Republican Party is being associated with the white nationalist movement that has been encouraged by Trump. It would be ironic that the racism of the slavery issue that caused the creation of the Republican Party in the 1850s could now be the cause of the destruction of the Republican Party in the 2020s.
Not all Republicans are racists but if you are a racist the chances are you are a Republican.