All politicians (and scientists, and pundits, and butchers, bakers, and candlestick-makers) start out as young people. If you're older than your opponent you can fire back by stating that young debaters aren't as good.
A leader is one who leads, and others follow because they believe the leader is on the right path. This is not the same as a politician, who is one who operates in the political arena to govern. Many politicians are not great leaders, just as many leaders aren't great politicians. Lyndon Johnson was a great politician, but not a great leader. George S. Patton was a great leader who would have been lost in politics.
Some leaders make themselves known early, such as Alexander the Great, or Joan of Arc.
