After a lengthy exchange in which Donald Trump rambled about how China will take advantage of the Trans-Pacific Partnership, Sen. Rand Paul did some on-the-spot fact-checking at the Republican debate tonight, pointing out that China is not a part of the trade deal and may, in fact, lose because of it.

Here's the exchange, which began after moderator Gerard Baker asked Trump about TPP:

Donald Trump: Almost everybody takes advantage of the United States. China in particular, because they're so good. It's the number one abuser of this country. And if you look at the way they take advantage, it's through currency manipulation. It's not even discussed in the almost 6,000-page agreement.…

Rand Paul: Hey, Gerard, you know, we might want to point out China is not part of this deal.

Gerard Baker: True, it's true.… Isn't that part of the problem, when I say, senator, that if this deal is not ratified by the US Senate, then it would actually give China an opportunity to grow its economic leadership, which it's been seeking to do, and if the US is unable to take part in this trade deal with these countries in Asia, China will take the lead?

Rand Paul: There is an argument that China doesn't like the deal, because in us doing the deal we will be trading with competitors. You're exactly right.