Answer: It's possible that Barack Obama quoted the Constitution at the beginning of a speech to emphasize the importance of the founding principles of the United States and to connect his message to the core values of the nation. By referencing the Constitution, Obama may have been trying to establish a sense of historical and cultural significance for his speech and to ground his arguments in the principles of the country's founding documents.
Additionally, quoting the Constitution may have served to emphasize the importance of the rule of law and the protection of individual rights, especially if the speech was focused on issues related to government, politics, or social justice.
It's also possible that Obama was seeking to build credibility with his audience by drawing on the authority of the Constitution, or to evoke a sense of patriotism and national unity by invoking the shared history and values of the country.
Overall, the reasons why Obama might have quoted the Constitution at the beginning of a speech would depend on the context and content of the speech, as well as his intended goals and audience.
Step-by-step explanation: