South Korea's increasingly polarized political landscape necessitates an analysis of presidential rhetoric's role in shaping governance and ideological narratives. This study investigates the frequency and strategic use of the term "Jayu" (freedom or liberty) in presidential speeches, particularly focusing on President Yoon Suk Yeol's administration. The study posits that the prominence of "Jayu" in Yoon's speeches is not coincidental but rather a deliberate rhetorical strategy reflecting his conservative ideology and political goals. This analysis extends beyond Western democracies, offering insights into the nuances of political discourse in a significant Asian democracy. By examining over 8,800 speeches from 1948 to 2023, this research provides a broad historical context for understanding the evolution and impact of presidential rhetoric on Korea's ideological and policy landscape. The study employs a mixed-methods approach integrating computational techniques like Natural Language Processing (NLP), time-series analysis, and Latent Dirichlet Allocation (LDA) for a comprehensive analysis across three distinct phases: examining the correlation between presidential political alignment and Jayu usage; comparing Yoon's Jayu usage to his predecessors; and identifying salient terms in each president's speeches using LDA.

The study draws upon diverse theoretical frameworks to analyze political language, symbolism, and rhetoric. It incorporates the work of Wittgenstein on language's contextual understanding, Bourdieu and Foucault on the relationship between language and power, and Edelman on the symbolic construction of political realities. The study also considers existing literature on presidential rhetoric and the strategic use of symbolism in shaping public discourse and managing media narratives. The examination extends to the historical evolution and ideological implications of "Jayu" and "Minju" (democracy) in South Korean politics, highlighting the contrasting uses of these terms by conservative and progressive factions. The literature review underscores the importance of analyzing political language within its historical, social, and cultural contexts.

The study uses a multi-faceted methodological approach combining qualitative and quantitative methods. Data was collected through web scraping of presidential archives and official government websites, compiling over 8,800 speeches from 1948 to October 2023. The data was processed to create variables representing daily mentions of "Jayu" and "Minju." Time-series analysis, specifically using an Auto-Regressive Moving Average with exogenous factors (ARMAX) model, was employed to investigate the relationship between presidential political affiliation (conservative or progressive) and the frequency of "Jayu" and "Minju" mentions. The ARMAX model accounts for the temporal dependencies inherent in time-series data and incorporates the "Party" variable as an exogenous factor. The Augmented Dickey-Fuller test was used to ensure the stationarity of the data. A comparative analysis was conducted to examine the average mentions of "Jayu" by each president and to highlight differences in usage patterns between conservative and progressive administrations. Finally, Latent Dirichlet Allocation (LDA) was used to extract the most salient terms from each president's speeches, allowing for a thematic comparison across presidential tenures. The study carefully delineates periods for analysis (Full Period, Post-Democratization, Post-New-Right Movement, and Post-Impeachment) based on significant political events in South Korea, further validated using the Chow test and Cumulative Sum (CUSUM) test.

The analysis revealed a statistically significant positive relationship between conservative political affiliation and the frequency of "Jayu" mentions in presidential speeches across different time periods, even after controlling for temporal dependencies. This association is particularly strong in the Post-New Right Movement and Post-Impeachment periods. President Yoon Suk Yeol's average mentions of "Jayu" are significantly higher than all his predecessors, exceeding even the averages for conservative presidents. The difference and ratio between "Jayu" and "Minju" mentions were also highest for President Yoon. LDA analysis showed a thematic shift in presidential rhetoric over time; while earlier presidents emphasized themes related to governance, national development, and the public, Yoon's speeches are predominantly characterized by the use of "Jayu", especially in key addresses like inaugurations. The analysis of inaugural addresses showed a stark contrast between the numerous mentions of "Jayu" in Yoon's address and the minimal use by his predecessors, highlighting the deliberate deployment of this term as a rhetorical strategy. The study further analyzed the specific policy orientations of the Yoon administration related to labor, market regulations, social welfare, and foreign policy towards North Korea, linking these to the consistent emphasis on "Jayu" as a symbol of conservative ideology.

The findings strongly support the hypothesis that President Yoon Suk Yeol's frequent use of "Jayu" is a calculated rhetorical strategy. The significant correlation between conservative affiliation and "Jayu" usage, particularly amplified in recent decades, indicates that the term serves as a powerful symbol of conservative ideology and is strategically deployed to rally support and define the administration's agenda. President Yoon's extensive use of "Jayu", especially in contrast to his predecessors' emphasis on "the public," demonstrates a shift in rhetorical strategy and prioritization of ideological messaging over broader national unity. The analysis of Yoon's policy positions further reinforces this interpretation, revealing a consistent alignment between his rhetoric and his pro-business, market-oriented, and anti-communist policies. The study's findings contribute to a deeper understanding of the role of symbolic language in shaping political discourse and public perceptions in South Korea, particularly highlighting the dynamics of political polarization.

This study demonstrates a clear and significant association between conservative political affiliation and the strategic use of "Jayu" in South Korean presidential rhetoric. President Yoon Suk Yeol's unprecedented emphasis on "Jayu" represents a deliberate rhetorical strategy designed to mobilize conservative support, define his administration's agenda, and potentially exacerbate political polarization. The study highlights the need for further research investigating the societal impacts of such divisive political language in increasingly polarized political environments.

The study acknowledges limitations stemming from the focus on a specific keyword and the potential variations in interpretation resulting from the use of specific NLP tools (Okt tokenizer) and stop word lists. Future research could benefit from a more comprehensive keyword analysis and cross-lingual comparisons. The analysis focuses primarily on the president's speeches, and a more nuanced understanding would require incorporating additional forms of political communication, such as interviews, press conferences, and social media interactions. Finally, the study's interpretation of historical political periods might be subject to alternative perspectives, emphasizing the need for further contextualization.