When Is It That We Really Have One President At A Time?

When asked about the situation between Hamas in the Gaza Strip and Israel, Mr. Obama cops-out on any comment by saying this country only has one President at a time. On the other hand, however, he has been bombarding the airways with comments about every domestic issue possible; from national security to social security. At the same time he is driving Congress to accept his plans for an economic bailout "prior" to his arrival in the Oval Office. So, sometimes two Presidents? Sometimes not? Which is it?