Answer:
1. This is our chance to answer that call. This is our moment. This is our time — to put our people back to work and open doors of opportunity for our kids; to restore prosperity and promote the cause of peace;
2. We may not get there in one year, or even one term, but America — I have never been more hopeful than I am tonight that we will get there.
3. It's been a long time coming, but tonight, because of what we did on this day, in this election, at this defining moment, change has come to America.
Explanation:
Carpe diem is the act of seizing the moment without much thought about tomorrow. When used in a speech, the speaker emphasizes on the present moment without postponing matters or giving much thoughts to the future. President Obama in his speech made a lot of reference to this style of speech by laying much emphasis on the night when he won the election.
For example, in the third example above, he emphasized that because of what was done on the election day, the defining moment, change had come to America.
