Justice Amy Coney Barrett, 52, is the youngest member of the Supreme Court and the junior member of its conservative supermajority. Last week, she completed what was only her third full term.

Yet she has already emerged as a distinctive force on the court, issuing opinions that her admirers say are characterized by intellectual seriousness, independence, caution and a welcome measure of common sense.

In the term that ended last week, she delivered a series of concurring opinions questioning and honing the majority’s methods and conclusions.

She wrote notable dissents, joined by liberal justices, from decisions limiting the tools prosecutors can use in cases against members of the Jan. 6 mob and blocking a Biden administration plan to combat air pollution. And she voted with the court’s three-member liberal wing in March, saying the majority had ruled too broadly in restoring former President Donald J. Trump to the Colorado ballot.

The bottom line: Justice Barrett was the Republican appointee most likely to vote for a liberal result in the last term.

That does not make her a liberal, said Irv Gornstein, the executive director of Georgetown University’s Supreme Court Institute.