Article I Section VII of the US Constitution requires that budget bills originate in the House of Representatives. There they are deliberated until passed. Then the Senate has the task of debating, changing, and passing their own version of the bill. Whereupon both legislative houses must reconcile the differences in conference committee. Once done this is passed to the President, who signs or vetoes the law per Executive authority.
In the current congressional budget impasse, the House currently threatens to refuse passing a budget unless riders which would change already passed law are changed. In merely weeks US sovereign debt is under threat of default. Were that to happen the solvency and good credit of the United States would face ruin resulting in a potential worldwide economic calamity.
At the essay following the link I argue that the House is essentially usurping authority from the Senate to deliberate and reconcile in conference by threatening default. That were this precedent set it would give the House a defacto veto over already passed law, diminishing the role of the Senate in ways US founders never intended. And further, that this action is likely unconstitutional.