WASHINGTON—The American Bar Association on Tuesday issued its report on Supreme Court nominee Merrick Garland, praising the federal appeals judge as among the finest jurists to serve on the federal bench.

There was little doubt that the ABA, which has reviewed the qualifications of federal judicial nominees since 1953, would give Judge Garland the highest of its three ratings, “well qualified.” But the 26-page report, produced by panels of practicing attorneys, law professors and others, was remarkable for the praise it showered...