The Supreme Court has been moving at a sluggish pace in issuing decisions this term, entering the second half of June with more than 20 left to go. That is not terribly different from the last two terms, when the pace at which the court issued decisions started to slow.

Over the almost two decades in which Chief Justice John G. Roberts Jr. has led the court, it has on average decided 72 percent of argued cases by this point in the term, according to data compiled by Lee Epstein, a law professor and political scientist at the University of Southern California. The corresponding number for the previous court, led by Chief Justice William H. Rehnquist from 1986 to 2005, was 78 percent.

But in the last three terms, the court has decided no more than 62 percent of the term’s cases by June 14.

There are two main theories for why the court has started moving slowly, and they reinforce each other. The first is that the proportion of blockbusters is high, in this term in particular. In the coming weeks, the justices will weigh in on criminal charges against former President Donald J. Trump, abortion, guns, social media, homelessness, the opioid crisis and the power of executive agencies.

Of the 23 remaining cases, perhaps a dozen of them have the potential to reshape significant parts of American society.