Put simply, tariffs are a tax on imports. Here's what Donald Trump did with them in his first term and how they impact the economy.

While the announcement is almost certainly bluster to bring attention to illegal immigration and fentanyl smuggling, there are several reasons why it is so risky.

Rep. Henry Cuellar believes Trump's threat of tariffs will "definitely get Mexico to the table so we can solve the problem about immigration and fentanyl."