I don't agree. [With all due respect to a Rabbi who has created a religious revolution and is probably the most successful rabbi in the US. In contrast, I have done almost nothing in my life to help the Jewish people, spread Torah and change the world. So despite my disagreement, he remains much much better than me on multiple levels].
First of all: Talmidei Chachomim can determine which candidate promotes Jewish values. If, for example, one candidate is in favor of forcing people to work on Shabbos and the other is against, then the Torah would dictate whom we vote for. If one candidate is in favor of banning wearing religious symbols such as a kippah and the other isn't - then it is a no-brainer whom we choose. Look at what Trump stands for, look at what Biden stands for and see who is better for the Jews. Look at who their advisors are. Look at their records. OF COURSE there are Halachic and Hashkafic reasons to vote for a specific candidate. [It goes w/o saying that the candidates' relationship to the Jews, Jewish values and Israel are not the ONLY reasons to vote for a candidate - although those are primary. Other things must also be taken into account and factored in].
Second: In Israel, I am not aware of any Rabbonim who say or have said since the birth of the State that it is not a Rabbi's place to express an opinion about whom to vote for. Rav Avraham Shapira ztz"l, RY Mercaz HaRav and former Chief Rabbi wrote an article years back that it is אסור to vote for a secular party [in Israel] because it is considered מסייע בידי עוברי עבירה - aiding and abetting sinners. So how can one argue with ALL of the big Rabbonim in Israel??? The Chazon Ish!! The Brisker Rov!! Rav Shach!! Rav Ovadiah Yosef!! Rav Chaim Kneyevsky Shlita! Rosh Yeshiva after Rosh Yeshiva, Rav after Rav, Chasidishe Rebbe after Chasidishe Rebbe [including yours truly, who when I lived in Michigan, was known as the "Michiginner Rebbe"]! The list is endless. They all paskened who to vote for. The same applies not only to Charedi Rabbonim but to Religious Zionist ones as well. The Roshei Yeshiva even allow their students to be מבטל תורה in order to help with the election effort for a specific party! For the same reason that Rabbonim have a right to pasken whom to vote for in Israel, they do in Chutz La-aretz as well.
Third: Hakaras Hatov. If we as a community have a debt of gratitude to one of the candidates then it is the place of Rabbonim to tell people to express that gratitude at the ballot box. To be an ingrate is to be - ala the Ramban on the pasuk עם נבל ולא חכם - subhuman.
Fourth: The Torah should be our guide on ALL areas of life. This includes our voting preferences. Many laymen just don't have sufficient Torah knowledge to make the choice based on the Torah so they need the guidance of those who know more. Read Rabbi Lamm's drashos and see how he illuminated contemporary political issues in the light of Torah and tradition.
The downside is that it turns people off when they hear Rabbonim supporting a candidate they don't like. It causes people to associate Yiddishkeit with supporting that candidate and thus turns them off.
Also, politics is a dirty game and when you get into the game, you are liable to get dirty yourself...
But the pros of Rabbonim supporting a candidate outweigh the cons which is why Rabbonim [such as Rav Shmuel Kaminetzky] have endorsed one of the candidates. It is Pikuach Nefesh and Rabbonim have the right to express opinions particularly on Pikuach Nefesh.
