The Hortensian Law deprived the patricians of their last weapon against the plebeians, and thus resolved the last great political question of the era. No such important political changes occurred between 287 BC and 133 BC. The important laws of this era were still enacted by the senate. In effect, the plebeians were satisfied with the possession of power, but did not care to use it. The senate was supreme during this era because the era was dominated by questions of foreign and military policy. This was the most militarily active era of the Roman Republic.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): Why was the senate considered to be supreme during this time?
because the era was dominated by questions of foreign and military policy