Senator Chuck Schumer, Democrat of New York and the majority leader, on Thursday delivered a pointed speech on the Senate floor excoriating Prime Minister Benjamin Netanyahu of Israel as a major obstacle to peace in the Middle East and calling for new leadership in Israel, five months into the war.Many Democratic lawmakers have condemned Mr. Netanyahu’s leadership and his right-wing governing coalition, and President Biden has even criticized the Israeli military’s offensive in Gaza as “over the top.” But Mr. Schumer’s speech amounted to the sharpest critique yet from a senior…