DAMASCUS, Syria — As President Bashar al-Assad seeks re-election and promises victory over insurgents by year’s end, Syrian loyalists and regional analysts say that his success, if it materializes, could set him up for a new challenge: demands for change from core supporters who believe he owes his survival mainly to them.

Some loyalists say that the Syrians most responsible for keeping Mr. Assad afloat are newly aware of his dependence on them, and would push for a bigger share of power if they came to feel safe from the threat of insurgent revenge.

Paradoxically, Yezid Sayigh, an analyst at the Carnegie Middle East Center in Beirut, Lebanon, wrote recently, a short-term Assad victory “may be the only thing capable of paving the way for serious dissent to openly emerge from the regime’s own social constituencies and institutional base.”

Mr. Assad has survived largely thanks to the muscle, cohesion and sacrifices of two overlapping groups: fellow members of the minority Alawite sect, who disproportionately lead and serve in the security forces, and key military men from a variety of sects. Reeling from war losses and frustrated in some cases with the president’s policies, some have begun to say that they are entitled to more of the power, wealth and opportunity held close by Mr. Assad and his associates.