The State of Israel upon its founding in 1948 chose the Menorah to represent the Jewish People.
The reasoning may have had more to do with the fact that the Arch of Titus in Rome depicts the Jews carrying the Menorah into captivity with them. The Founding Fathers of the State of Israel saw the Menorah as a sign that the Jewish People had overcome the 2000 year old Roman Exile and had returned Home with their Menorah intact.
It is a Noble and important symbolism. However, the Menorah represents so much more than Ben Gurion et al had in mind. Parshat Beha'alotcha makes this very clear. "Hashem spoke to Moshe saying. Speak to Aaron and say to him: When you kindle the lamps, toward the face of the Menorah shall the seven lamps cast light."(8:1-2) "This is the workmanship of the Menorah, hammered-out gold; according to the vision that Hashem showed Moshe, so did he make the Menorah." (8:4) The Ramban points out right away that unlike the Korbanot which are in effect only when the Holy Temple stood, the lighting of the Menorah in the form of the Chanukah Menorah will occur even when the Temple has been destroyed.
The Ramban explains based upon Rabbeinu Nissim, The Holy One, blessed is he, said to Moshe, "Speak to Aaron and say to him." There will be another Temple inauguration one day that will involve the lighting of lamps, and through it I will provide miracles and salvation to Israel through your Descendants and a dedication that will be called by their name that is, the Chanukah Inauguration of the House of Hasmoneans."' This is the Power of the Menorah above and beyond all other instruments of the Mishkan and the Holy Temple. Now I turn to the depth of meaning of the Menorah. The Malbim (Rimzei HaMishkan, Shemot 25:37) says, "Everyone agrees that the Menorah alludes to the light of learning and knowledge, and I have already written that the Ark alludes to the wisdom of the Torah and prophecy, which is the wisdom that comes only by the appearance of G-d in revelation.
The Menorah in contrast alluded to that which a person can learn on his own, understanding gained through the power of his own intelligence…Rather it is found in those who are naturally endowed with intelligence and understanding, and they emanate intelligence and understanding of this sort to human beings…the fruit of this understanding are the seven sciences which humans invented using their own minds. It was represented by the seven shafts of the Menorah which allude to the light of the intellect, all of which faced the central lamp, which was Divine wisdom…" The power of the seven branches of the Menorah is further elucidated by the Sfat Emet who says that the seven shafts of the Menorah represents the days of the week highlighted by Shabbat which is the central shaft. As the light of the Menorah represents the light of Torah, the Torah is read on Shabbat to be a source of light for the six days of the week.
I would extend the symbolism further by adding that the Shabbat Shaft is in the center rather than at either end. The center shaft is the main part of the Menorah from which the six others originate. It is interesting that the days of the week are indeed set up on either side of Shabbat in a Halachic sense too.
For example one is permitted to say the Havdalah Prayer until Tuesday(the third day of the week). The fact that the Menorah has to be made from one piece of Gold that is beaten out also highlights how important Shabbat and the Divine Spirit of the central shaft are for the six branches. They are all inteconnected coming from the same source. The six days of the week could not function without Shabbat. It is the root and center from which all else emanates and flows. The State of Israel held a competition in 1948 for the best representative National Symbol and came up with the Menorah.
As I mentioned earlier it had a lot to do with the Menorah seen on the Arch of Titus. It also was tied to Isaiah 60 "Nations will come to your light and Kings to the brightness of your dawn". This is fitting and appropriate and a fulfillment of Isaiah's prophecy. Now to more practical matters concerning the Menorah. Does the Menorah from the Second Temple brought to Rome still exist? I have been personally involved in the search for the Menorah for over 30 years. One sighting of a Menorah (not necessarily the one taken to Rome in 70 CE) was made by Oscar Goldman Of Blessed Memory who did see a Menorah along with many Temple artifacts(utensils) in the Vatican in 1962. I have published on you tube my interview with Mr. Goldman on this subject.
According to many Historians the Romans kept the booty from their conquests in the center of Rome on display. The Menorah was apparently on display until 410 when the Visigoths led by Alaric sacked Rome. It is not clear what happened after. It is possible it was melted down for its gold value. I sincerely believe that that is not the case. The power of the Menorah is too great. The Visigoths converted to Christianity. It could be buried under a Church somewhere much as King Richard III (killed in 1485) was recently discovered buried in an area where a church once stood. It could still be in the Vatican although the Vatican has denied possessing it. The Vatican has denied having much of what Oscar Goldman of Blessed Memory indeed saw in 1962.
Oscar Goldman was a devoutly religious and upright Man who I personally believe 100%. The Vatican has many reasons to deny having the Second Temple Menorah. I do believe we will find the actual Menorah that Titus brought to Rome some day. In any case there is no denying the Power of the Menorah and the depths of its meaning. Shabbat Shalom