What are the political and economic limitations upon (a) fiscal policy and (b) monetary policy?

What will be an ideal response?

Political limitations on fiscal policy are the strongest because tax and spending policies are designed and ratified by Congress whose members are up for re-election every few years. Thus, it is difficult for Congress to enact cuts in spending or hikes in taxes which would be politically unpopular. Political limitations on monetary policy are less strong since the members of the Board of Governors are appointed to 14-year terms and are thus largely removed from political pressures. However, Congress does have the ultimate power to change the system and the members of the board, so they cannot be entirely oblivious to political impact of their decisions.
The economic limitations are closely related to the political, but would include the ability and willingness of the public to pay increased taxes or withstand cuts in government programs or to withstand the impact of a restrictive monetary policy. In other words, policies to fight inflation are limited by the severity of their impact on incomes and employment.
The economic limitations on expansionary policies are related to predictions about the future impact of such policies. In other words expansionary policies can over correct problems of a recession and create inflationary pressures in the future.