Don't like legislatipn that was passed by Congress and signed into law years ago? Well if Congress follows the logic of Senator Rafael Cruz, the answer is simple: threaten to shut down the government & not pay the bills which Congress itself has already agreed to pay until the law is undone.
It's really very simple.
If you are a Republican, contemplate the following scenario: it is the not too distant future we have a Republican President and a narrow Republican majority in Congress. The Republican President shepherds a bill through Congress and signs it into law. Legislation is enacted. Four years later, the Democrats take control of one of the two houses of Congress and immediately declare that they will hold the government hostage until the previously enacted law in overturned. No negotiation. No legislative process. Their way or the highway.
Does the above make sense to any Republican out there with even a quarter functioning brain? Of course it doesn't. But yet this is the precedent that Senator Cruz is setting for America, one in which we we no longer use the legislative process to change laws, but instead allow extreme political ideology and posturing for future office to determine whether or not the government is allowed to function.
Rafael Cruz is wrong. Very wrong. Don't like Obamacare? I'm not necessarily a fan either. But no one cause is so important that it justifying shutting down a government...unless that cause, apparently, is sucking up to the fringe* of American politics in a vain attempt be elected President one day.
(*) According to Gallup, about 22% of the voting population affiliates themselves with the "Tea Party". 27% view themselves as being an opponent of the "Tea Party".