RAMALLAH, West Bank — In the daily demonstrations here of solidarity with Gaza, a mix of sympathy and anguish, there is something else: growing identification with the Islamist fighters of Hamas and derision for the Palestinian Authority, which Washington considers the only viable partner for peace with Israel.

“Strike a blow on Tel Aviv!” proclaimed the lyrics of a new hit song blasting from shops and speakers at Monday’s demonstration, in a reference to Hamas rockets that made it nearly to Israel’s economic and cultural capital. “Don’t let the Zionists sleep! We don’t want a truce or a solution! Oh, Palestinians, you can be proud!”

Pop songs everywhere are filled with bravado and aggression. But this one reflects a widespread sentiment that does not augur well for President Mahmoud Abbas and his Palestinian Authority, which is rapidly losing credibility, even relevance. The Gaza truce talks in Cairo, involving Egypt, Turkey and Qatar, offer a telling tableau. The Palestinian leader seen there is not Mr. Abbas, but Khaled Meshal, the leader of the militant group Hamas, who seeks to speak for all Palestinians as his ideological brothers in the Muslim Brotherhood rise to power around the region.

Israel is also threatening Mr. Abbas, even hinting that it may give up on him, as he prepares to go to the United Nations General Assembly on Nov. 29 to try to upgrade the Palestinian status to that of a nonmember state. The Israelis consider this step an act of aggression, and even some Palestinians say it is somewhat beside the point at this stage.