US constitution

Please use Article I, section 8 of the U.S. Constitution, which is known as the enumerated powers clause, to evaluate the constitutionality of the following government actions.  Which powers of Congress allow the national government to take each of the actions described?  Keep in mind, there may be more than one… or there may not be a power of Congress related to the action (in which case the action would be unconstitutional). 
Congress passes a law, which asks states to establish a system of standardized testing for K-12 schools and to track student performance against state-mandated standards. If states do not create these exams and standards, they lose a portion of the federal education funding for which they might be eligible.
Congress creates a program to promote the prices of American agricultural products by offering low income families a subsidy to purchase food.
Congress passes a law requiring the US President to seek congressional authorization within 60 days of deploying American military personnel in foreign territory.
Congress passes a law requiring states to raise their drinking age to 21 or lose 10-25% of their federal transportation grants.
Congress passes a law that prevents the Centers for Disease Control from using any money allocated by Congress to study the health consequences of gun violence.
Congress passes a law defining who may jointly file federal taxes and claim federal tax benefits related to marriage. It also states that no state can be required to observe any definition other than the federal definition.
VERY IMPORTANT!!  After addressing each of these examples, please describe any trends that you see.