(CNN) Lawmaking on Capitol Hill is often compared to sausage-making because the process can be grisly and gross and, at least for the idealists out there, enough to turn your stomach inside out.

Let's start with why it gets so messy.

When lawmakers decide to go big, they need to stitch together the smaller bits to satisfy their colleagues. If a particular group, or faction, wants one thing, the sausage chefs often tie it to another -- something the first bloc might not want but are willing to swallow to assure their primary goal.

Deals get done, then bills get passed. Or they don't, and they don't. It all depends on legislators finding the right balance, and binding up the necessary votes. For Senate Republicans this year, the "yeas" have been tough to corral. They couldn't find the 50 required, a lower threshold created by some legislative jujitsu called "budget reconciliation," to unwind Obamacare despite months of trying.

Now they're at it again, same rules, attempting to pass a sweeping tax cut for corporations, the wealthy and parts of the middle class. Here's the catch: Because they are using the budget reconciliation process (again), the legislation cannot raise the long-term deficit.

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