The president is not mentioned. That would add the specificity you need, but it's not there.
Walt
...because he does not have the power. The Constitution gives the power only by way of Article I, Section 9, Clause 2. That same Constitution also says that clause belongs to the legislature. Such a statement is inherently exclusive. I cannot give an apple to you, Walt, and at the same time give that same apple to 4CJ, Non-Seq, and billbears.