美国有线新闻 CNN 参院共和党启动核选项 力保特朗普大法官提名（在线收听）

We're getting started in the U.S. capital, where Senate Republicans have been working to get President Donald Trump's Supreme Court, Judge Neil Gorsuch, confirmed to the high court. A few Democrats said they'd vote for Judge Gorsuch as well, but most of them have been working to block the nomination. And in the back and forth between the political parties, both a filibuster and the nuclear option came into play yesterday.

We defined these terms on Wednesday's show. You can find that in our archives at CNN10.com.

What's interesting about the filibuster and the nuclear option is that neither of them is actually mentioned in the U.S. Constitution. The American governing document allows the congressional chambers, the House and Senate, to set their own rules.

The filibuster is a tradition, a sort of rule that allows a minority party to block a nominee or piece of legislation, and a nuclear option is a rule change that allows a majority party to get around that block and vote with a simple majority.

Republicans control the Senate. They have 52 seats. While Democrats and the independents who vote with them have 48 seats.

After yesterday's move to invoke the nuclear option, both parties have now used the controversial rule change and this time around, it was expected to lead to the confirmation of Judge Gorsuch to the Supreme Court.

CHRIS CILLIZZA, CNN POLITICS REPORTER: The one thing to know about the nuclear option is you may not understand it, but it does really matter.

SUBTITLE: The One Thing: The "nuclear option".

CILLIZZA: The nuclear option is sort of a common place term for a way in which the filibuster rules of the Senate are end run, usually to stop debate on any matter in front of the Senate, you need to get 60 votes.

But if you use the nuclear option, you take that 60-vote margin and take it down to a majority 51-vote threshold. In 2013, Harry Reid, after months and months of threatening to deploy the nuclear option actually did it.

SEN. HARRY REID (D), NEVADA: It's time to get the Senate working again, not for the good of the current Democratic majority or some future Republican majority, but for the good of the United States of America.

CILLIZZA: The filibuster, whether real or threaten, had always been a way that the Senate distinguish itself from the House. The House very much runs in a "majority rule" rule. If you have the votes, you have the votes. In the Senate, in order to close off that debate, which means to force an actual majority vote, you needed always to have 60. It required typically some bipartisan consensus building, because neither party often had 60-plus seats in their control.

When you remove that, you start to slide even further down the slippery slope that Harry Reid started us all on in 2013. If we've already wiped out the use of the traditional filibuster, that 60-vote margin on several things including Supreme Court nominees, what's to stop either this majority or the next majority, Democrat or Republican, from instituting it on legislative matters? And at that point, the Senate fully becomes the House.