Reagan made several references in his speech at Bitburg Airbase to Kennedy's earlier "Ich Bin Berliner" speech. How does he build upon the point...

Besides just being a great speech technique, Reagan was
emphasizing that the American commitment to protecting West Germany and West Berlin was
unchanged from the early 1960s when Kennedy made his speech.  Kennedy's point was to
show solidarity with our German allies in the wake of Soviet construction of the Berlin
Wall, his own speech reiterating the commitment Harry Truman had made during the Berlin
Airlift in 1948-49.

Reagan was all about symbolism, and in
addition to boosting the morale of Germans, he was also issuing a challenge to Soviet
leaders to bring down the Iron Curtain and allow Germany to be reunified.  I don't think
he believed it would happen anytime in the near future, but as another speech in front
of the Brandenburg Gate made clear, ("Mr. Gorbachev, tear down this wall!") Reagan
considered the Germans one of our closest allies.