The wording of the Pocket Veto Clause of the Constitution that a bill shall not become law if “the Congress by their Adjournment prevent its Return” by the President—expresses the assumption that adjournments ordinarily make the return of a bill impossible, but the clear structural rule established by the Clause applies to all adjournments in the constitutional sense, even if Congress has taken measures to make the return of a bill possible.
The drafting history of the Pocket Veto Clause shows an intent to avoid excessive periods of uncertainty about the fate of bills passed by Congress.
Ordinary legislation expressing Congress’ view about the category of adjournments covered by the Pocket Veto Clause is inappropriate, because such legislation cannot change the meaning of the constitutional terms.
Presidents Ford and Carter may have purported to return bills that, under the Constitution, could only be pocket-vetoed. Thus, the bills they believed they had return-vetoed may in fact have been pocket-vetoed instead. As far as we know, however, this has no practical effect.
Congress can avoid application of the Pocket Veto Clause during brief adjournments by scheduling presentment of bills so that the tenth day after presentment does not fall during an adjournment of either House that is longer than three days.