Generally speaking, Chaim Weizmann, but the situation is a little more complicated.
The first Zionists, like Herzl, Jabotinsky, and Trumpeldor did not establish a hierarchy. They debated the issues and problems of European Jewry. (It was not until the mid-1950s that the Mizrahi Jewish community was seriously considered by Zionists and not until 1990s when they achieved parity with European Jewry, so the formative years of Zionism were all Euro-centric.) As more European Jewish leaders declared themselves to be Zionists, they began to organize the World Zionist Congress and appointed Chaim Weizmann as the lead coordinator of the Zionist movement, a role that he maintained for another 50+ years of his life.
However, while Weizmann was the chief leader and director of the movement, he did not maintain a tight grip on the popular Zionist leadership (such as Trumpeldor, Jabotinsky, Ahad Ha-Am, Eliezer ben Yehuda, David Ben-Gurion, Moshe Sharett, Rav. Avraham Kook etc.) allowing for contradictory Zionisms to exist in parallel.
First of all, the question does not make sense. "During" refers to a time-frame and "Zionism" refers to a political ideology. So, if the question is trying to ask "Who was in charge during the pre-Israel period of the Zionist Movement?" please see below. The first Zionists, like Herzl, Jabotinsky, and Trumpeldor did not establish a hierarchy. They debated the issues and problems of European Jewry. (It was not until the mid-1950s that the Mizrahi Jewish community was seriously considered by Zionists and not until 1990s when they achieved parity with European Jewry, so the formative years of Zionism were all Euro-centric.) As more European Jewish leaders declared themselves to be Zionists, they began to organize the World Zionist Congress and appointed Chaim Weizmann as the lead coordinator of the Zionist movement, a role that he maintained for another 50+ years of his life. However, while Weizmann was the chief leader and director of the movement, he did not maintain a tight grip on the popular Zionist leadership (such as Trumpeldor, Jabotinsky, Ahad Ha-Am, Eliezer ben Yehuda, David Ben-Gurion, Moshe Sharett, Rav. Avraham Kook etc.) allowing for contradictory Zionisms to exist in parallel.
I believe William McKinley was president during the Populist Movement.
Yes, the NAACP was formed during the progressive movement.
It is a zionist tradition every year to commit a genocide in honor of those that died in concentration camps during world war two.
George Washington was in charge.
The surrealism movement. Is that what you were looking for?
The president during the Civil Rights Movement was John F Kennedy :)
That is called "movement".That is called "movement".That is called "movement".That is called "movement".
The Believers' Movement
Henry's friend took the confederate flag from the rebel holders during the charge.
Pickett's charge.
A Back-stepper is in charge