The observation that centrist and centre-left political parties have been facing setbacks while centre-right parties have been in ascendancy globally is a prominent trend in contemporary politics, particularly evident in many European democracies, North America, and parts of Latin America. This shift reflects deep-seated societal anxieties, economic transformations, and evolving political landscapes.

Reasons for Setbacks of Centrist and Centre-Left Parties:

1. Economic Discontent and Inequality: Many centre-left parties, traditionally champions of social welfare and economic equality, have struggled to effectively address rising income inequality, stagnant wages, and job insecurity in the wake of globalization and financial crises (e.g., 2008). Their traditional working-class base often feels abandoned or that these parties have become too aligned with corporate interests.
2. Globalization's Discontents: Centre-left parties often supported globalization, free trade, and open borders. However, the perceived negative consequences—such as job displacement, downward pressure on wages, and cultural erosion—have alienated segments of the electorate, pushing them towards more protectionist or nationalist right-wing alternatives.
3. Immigration and Identity Politics: Centre-left parties generally advocate for more inclusive immigration policies and multiculturalism. This stance has often clashed with growing concerns about national identity, cultural change, and the perceived strain on public services, leading some voters to gravitate towards parties offering stricter immigration controls and a stronger emphasis on national identity.
4. Loss of Traditional Base: The decline of traditional industrial sectors and the rise of the gig economy have fragmented the traditional working-class voter base of centre-left parties. Simultaneously, the rise of 'post-materialist' values among some urban, educated voters has sometimes led to a disconnect with the broader electorate.
5. Lack of Clear Ideological Vision: In an attempt to appeal to a broader electorate, some centrist and centre-left parties have been perceived as lacking a distinct ideological vision, becoming too similar to their centre-right counterparts. This 'third way' approach has sometimes led to voter apathy or defection to more ideologically distinct parties, both on the left and the right.
6. Rise of Populism: Both left- and right-wing populist movements have siphoned off voters from the traditional centre. Right-wing populism, in particular, has often been more electorally successful in tapping into public anger against elites, immigration, and globalization.

Reasons for Ascendancy of Centre-Right Parties (and often the far-right):

1. Nationalism and Sovereignty: Centre-right parties often emphasize national sovereignty, border control, and cultural preservation, resonating with voters who feel threatened by globalization, immigration, and supranational institutions.
2. Law and Order: A strong stance on crime, security, and national defense appeals to voters concerned about social stability and safety.
3. Economic Conservatism: Promises of lower taxes, deregulation, and business-friendly policies attract segments of the middle class, entrepreneurs, and the business community.
4. Effective Populist Messaging: Many centre-right and far-right leaders have successfully adopted populist rhetoric, directly addressing public grievances, distrust of elites, and a desire for strong leadership.
5. Exploitation of Crises: Right-wing parties have often capitalized on various crises (economic downturns, migration flows, perceived threats to national security) to offer seemingly decisive and straightforward solutions.

Conclusion: This global political realignment is not uniform, and counter-trends exist. However, the general shift reflects a profound re-evaluation by electorates of the promises and failures of traditional political establishments. It highlights a growing demand for parties that address concerns about economic security, national identity, and effective governance, often leading to a preference for more conservative or nationalist platforms over traditional centrist and centre-left offerings. This trend poses a significant challenge for centre-left parties to redefine their purpose and reconnect with a disillusioned and anxious electorate.