Who is the new leader of Klal Yisrael?

“Can there be an executive without a state?” An excellent and fundamental question. Inasmuch as an institution “does,” in theory, the executive would be the part that is “doing.” I think.

The legislative from Sinai idea is that the law is divinely originated, not man-made. While we still inherently (must) have a power to interpret, the power to enact, these days, is not clear, and would only be within the rigid rubric from Sinai.

Involved laypersons would be the non-rabbis, who are trying to act upon the rabbinic interpretation of the laws from Sinai and regulations added thereafter.

Obviously this is a whimsical and theoretical discussion. But aren’t these fundamental structures important to define?

Stop trying to reinvent Judaism to fit Western constructs. Judaism is a monarchy and certainly not a democracy.

Joseph, the Netziv (He’emek Devar Devarim 17:14) says:
“ואמרת: אשימה עלי מלך” – אין הפירוש “אמירה” כמשמעו בפה, אלא כלשון (דברים יב כ): “ואמרת אוכלה בשר”וכדומה.
אכן, לפי לשון זה היה במשמע שאין זה מצווה במוחלט למנות מלך אלא רשות, כמו ‘ואמרת אוכלה בשר’; והרי ידוע בדברי חז”ל דמצווה למנות מלך! ואם כן, למה כתיב ‘ואמרת’?
ונראה, דמשום דהנהגת המדינה משתנה, אם מתנהג על פי דעת מלוכה או על פי דעת העם ונבחריהם, ויש מדינה שאינה יכולה לסבול דעת מלוכה, ויש מדינה שבלא מלך הרי היא כספינה בלי קברניט, ודבר זה אי אפשר לעשות על פי מצוות עשה, שהרי בעניין השייך להנהגת הכלל נוגע לסכנת נפשות שדוחה מצוות עשה, משום הכי לא אפשר לצוות בהחלט למנות מלך, כל זמן שלא עלה בהסכמת העם לסבול עול מלך, על פי שרואים מדינות אשר סביבותיהם מתנהגים בסדר יותר נכון, או אז מצוות עשה לסנהדרין למנות מלך…
ומשום הכי כתיב ‘ואמרת’, שיהא העם מבקשים כך, אז ‘שום תשים’.
ומכל מקום, אין סנהדרין מצווים עד שיאמרו העם שרוצים הנהגת מלך, ומשם הכי כל משך שלוש מאות שנה שהיה המשכן נבחר בשילה לא היה מלך, והיינו שלא היה בזה הסכמת העם.
Not only is the public’s acceptance necessary to appoint any official (Berachot 55a) but they can also even recall a king (Yerushalmi Chaggiga 3:2 and Responsa Avnei Nezer YD 312:15). Thissi quite democratic.

Frum, the government may not give official status to any religious group. However, actually prohibiting voluntary communities would violate the Free Exercise clause. A law banning an Sharia courts was struck down by the Tenth Circuit (Awad v. Ziriax, et al, No. 10-6273 (10th Cir. 2012)). This would also apply to establishing battei din to adjudicate disputes. Basically, the government may neither help nor hinder religion.

Re separation of Powers:
John Fortescue (c. 1394–1479) was chief justice of Britain’s high court and his classic In Praise of the Laws of England . Fortescue held there that the English constitution limited the powers of the monarch under the traditional laws of England

in the same way that the powers of the Jewish king in the Mosaic constitution in Deuteronomy are limited by the traditional laws of the Israelite nation. This is in contrast with the Holy Roman Empire of Fortescue’s day, which was supposedly governed by Roman law, and therefore by the maxim that ‘what pleases the prince has the force of law,’ and in contrast with the kings of France, who governed absolutely.

Fortescue laid out “what later tradition would call the separation of powers and the system of checks and balances.” He linked “the character of a nation’s laws and their protection of private property to economic prosperity, arguing that limited government bolsters such prosperity, while an absolute government leads the people to destitution and ruin.” His work, adds Hazony and Haivry

“the belief that through long centuries of experience, and thanks to a powerful ongoing identification with Hebrew Scripture, the English had succeeded in creating a form of government more conducive to human freedom and flourishing than any other known to man.”

the 17th century jurists John Selden,

Hugo Grotious expounded further on this

FYI The torah DOES belive in Seperation of Powers, this was one of the main Averios of the Hashmonim, they were Cohanim and not supposed to be the Kings as well

HaGaon HaRav Elya Brudny shlit”a has joined the Moetzes Gedolei HaTorah of the Agudas Yisroel.

Rav dov landau
Rav chaim
Rav Gershon
Rav yaakov Meir
Rav mordechai gross
Belzer rebbe
Rav shlomo Miller

(Even though this conversation is long over,) you won’t find every frum community accepting one gadol to be the Gadol Hador. There doesn’t “HAVE” to be one Gadol Hador. It won’t happen until we get out of galus.
For Example: I might say that in the later 1900’s the Lubvaitcher Rebbe was the Gadol Hador. A Satmar Chossid will believe that the Satmar Rebbe was the Gadol Hador. A Litvack will say a different posek. The Sephradim also. To have one posek who everyone follows will simply not happen until moshiach.
Everyone should follow their own Rov to pasken halacha.