To activists, the Senate can be frustrating. It works slowly, the schedule is unpredictable, and everything is decided by negotiation. And the politics between Senators, factions of Senators, and the two parties are rarely transparent - so it's never easy for an outside observer to know what's going on.

Senate "holds" are a perfect example. Kagro X lays out the skinny here. But the short version: a Senator's hold is a threat to filibuster, but is only as durable as the holding-Senator's allies; if your caucus won't back you, the Majority Leader can essentially challenge a hold owner's threat that the bill will face a filibuster.

And while no Senator respects the slow procedural tradition more than Harry Reid, Tom Coburn went too far:

Majority Leader Harry Reid has had it up to here with Tom Coburn, the Senate's scourge of excessive spending and pork-barrel earmarks. Mr. Reid is telling reporters he will no longer tolerate the Oklahoma Republican blocking about 100 bills using the power Senate rules give individual member to stop legislation from coming to a floor vote. Mr. Coburn objects to many of the bills because he says they would enrich special interests and private developers at the expense of taxpayers.

What kind of legislation, pray tell, is Coburn holding up? Just two examples of many:

S.911 is one:

A bill to amend the Public Health Service Act to advance medical research and treatments into pediatric cancers, ensure patients and families have access to the current treatments and information regarding pediatric cancers, establish a population-based national childhood cancer database, and promote public awareness of pediatric cancers.

And S.1183 (known as the Christopher and Dana Reeve Paralysis Act) is another:

A bill to enhance and further research into paralysis and to improve rehabilitation and the quality of life for persons living with paralysis and other physical disabilities, and for other purposes.

Coburn isn't following Senate procedure, he's exploiting it. And since Senate Republicans insisted on wedding themselves to President Bush the last few years, they're not so politically strong right now. So Reid is moving:

So Mr. Reid is taking the unusual step of assembling a package of bills that Mr. Coburn has stopped, forming an omnibus bill and ramming them through the Senate before it leaves for its August break.
...
Mr. Reid's decision now puts added pressure on Mr. Coburn's fellow Republican senators. An omnibus bill can proceed to a floor vote if 60 Senators agree to cut off debate. With many GOP Senators having inserted provisions into the bills Mr. Coburn is blocking, they will be torn between supporting their colleague in his fight against excessive spending or risking losing projects for their state. Mr. Reid's move is a clever way to force Republicans to choose between their self-proclaimed principles and pork. It will be interesting to see just how many side with Democrats in their effort to roll over Mr. Coburn.

In the Senate, your party can't stay powerful forever. Republicans spent so long wringing every last drop of political capital from their position. And now they're dry.