What characterizes the Sixth Party System according to the provided information?

The Sixth Party System is characterized by intense and polarized competition primarily between the Democrats and Republicans. This period is marked by a backdrop of significant political and social upheaval, which contributes to a chaotic political climate. Issues such as race, immigration, and social movements have led to a heightened sense of partisanship, with both major parties firmly aligning themselves with distinctive ideological bases. This polarization results in political behavior that often appears chaotic, with both parties struggling to retain loyalty from traditional bases while appealing to shifting demographics.

In contrast to the other options, which suggest different aspects of party dynamics, this understanding captures the essence of the current political landscape. While there may indeed be fluctuations in party affiliation and a rise in independents, the defining feature of the Sixth Party System remains the pronounced conflict and disorder evident in the interactions between the two dominant political parties.