Answer:
1. Can a president fix problems without the support of Congress?
While presidents have many powers, and these powers have been increasing in recent times, most structural changes and difficult problems require the help of Congress, for example, raising taxes, or passing constitutional amendments.
Why do presidents make promises to get elected and why do people continually believe these promises?
Presidents make promises because they need to present a vision of the future for the nation. A president is not only someone who executes policy, but who also proposes policy. People believe these promises because presidents are usually good at being convincing.
Can one person be held solely responsible for all problems faced by
our country?
Not at all, let alone in a country like the U.S. where power is distributed among the three branches of government: legislative, executive and judiciary, and also, among the states.