WASHINGTON — The Supreme Court returns to the bench on Monday to confront not only a docket studded with momentous issues but also a new dynamic among the justices.

The coming term will probably include major decisions on affirmative action in higher education admissions, same-sex marriage and a challenge to the heart of the Voting Rights Act of 1965. Those rulings could easily rival the last term’s as the most consequential in recent memory.

The theme this term is the nature of equality, and it will play out over issues that have bedeviled the nation for decades. “Last term will be remembered for one case,” said Kannon K. Shanmugam, a lawyer with Williams & Connolly. “This term will be remembered for several.”

The term will also provide signals about the repercussions of Chief Justice John G. Roberts Jr.’s surprise decision in June to join the court’s four more liberal members and supply the decisive fifth vote in the landmark decision to uphold President Obama’s health care law. Every decision of the new term will be scrutinized for signs of whether Chief Justice Roberts, who had been a reliable member of the court’s conservative wing, has moved toward the ideological center of the court.