GEORGETOWN, Guyana — Swaying to the rhythms of Afro-Guyanese reggae, the protesters, descendants of African slaves and indentured laborers from India, gathered on the streets of Georgetown in a show of unity against the country’s president.

A few years ago, a gathering of members of Guyana’s two main ethnic groups, which have long been at opposite ends of the country’s political divide, would have been unusual.

But the protest in November, after President Donald Ramotar suspended Parliament in order to fend off a no-confidence motion, reflected an important change taking place in this tiny English-speaking country of just 740,000 people perched on the shoulder of South America.

Politics in Guyana have long been delineated by race. But a multiethnic movement that has emerged in recent years has given voice to a new generation of Guyanese who say that politics as usual has held the country back by favoring race over merit, undermining economic progress.