It's tariff time! President Trump's much-discussed and once-postponed tariffs on goods from China, Canada, and Mexico go into effect on Tuesday.

President Donald Trump's tariffs on Mexico and Canada are set to go into effect at midnight on Tuesday, setting up a second economic showdown with America's neighbors.

Trump's administration delayed imposing 25% tariffs on Canadian and Mexican goods last month following last-minute concessions from both countries. Officials from both countries have carried out negotiations with the Trump administration in recent weeks, but no agreement to reduce the incoming tariffs has been announced.

President Trump's free wielding of tariffs has been controversial, although in this case, the motivation for this is more related to smuggling rather than trade.

Peter Navarro, the White House senior counselor on trade and manufacturing, defended Trump's approach to tariffs on Monday. The White House has pointed to fentanyl and other drug trafficking across both the northern and southern borders to justify the tariffs.

"If you think about the problem, it starts in communist China with the precursor chemicals. It comes into Mexico and they make the fentanyl. But they also have these pill presses. So they do the counterfeits. And they're using Canada as a transit hub and secondary point to manufacture as well. So this is a Canada-Mexico-China thing," Navarro told CNBC.

It's important to note that before the 16th Amendment allowed the levy of the income tax, the federal government was funded in large part by tariffs. The federal government, however, has exploded in size and scope since then; but then, the Trump administration is taking some steps to deal with that, as well.

Trump's agenda is, a little over a month into his second term, proving popular with American voters:

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A recent Harvard CAPS-Harris poll showed 61 percent support for the statement: 

Placing reciprocal tariffs on countries that have tariffs on US goods

Canada, Mexico, and China all either have or are placing reciprocal tariffs on American goods. There's still time for more last-minute deal-making, but as of this writing, there have been no overtures from China or Canada. Mexico, perhaps realizing we can get along without Mexico's goods better than they can get along without ours, is trying to make a case for exemption from the tariff plan.

Mexican President Claudia Sheinbaum said Monday that her administration is waiting to see if President Trump makes good on his threat to impose 25% tariffs on Mexican imports Tuesday.

Her Cabinet secretaries for security and trade, among others, have been in constant communication with their U.S. counterparts and she said there was still the possibility she and Trump would speak Monday.

Tariffs, in history, have had mixed effects. The Smoot-Hawley Tariff Act of 1930, which laid tariffs on over 20,000 imported goods, was the second-highest tariff package in American history, and that act, along with the retaliatory tariffs by other nations, is considered by some to be one of the causes of the Great Depression.

Trump's tariffs, though, seem more a bargaining chip than an economic or fund-raising scheme.

This is a developing story. Stay tuned; we will bring you updates as things develop.