Trump's threatened Mexico tariffs would eat into the growth he likes to tout. 5 figures place the long-term risks into perspective.

Goldman Sachs lowered its quarterly gross-domestic-product forecasts for the rest of this year due in part to heightened trade-related uncertainty.

Jan Hatzius, the firm's chief US economist, said in a note to clients dated June 2 that the firm was reducing its third- and fourth-quarter GDP forecasts by 0.5 percentage points and 0.4 percentage points to 1.9% and 2% quarter-over-quarter, respectively.

That reflects "the drag from tighter financial conditions, heightened uncertainty, and eroded consumer purchasing power" with tariffs expected to boost inflation by 0.5 percentage points in the second half of this year.

Still, Hatzius expects growth to rebound next year.

"We expect growth to rebound moderately in 2020 as tariffs come off and financial conditions stabilize," the firm wrote.

Corporate earnings are set to take a hit this year and next due to Trump's tariffs on all of the goods the US imports from Mexico, Bank of America Merrill Lynch said Monday in a note to clients.

The firm cut its earnings-per-share forecasts for 2019 and 2020 due in part due to renewed trade tensions between the US and China and because of the newly proposed tariffs on Mexico.

"We estimate a 1% EPS hit from increased China tariffs," the firm said. "From tariffs on Mexico, we estimate a 0.6% drag in '19 & 1.5% in '20."

BAML lowered its 2019 earnings-per-share outlook to $166 from $168, marking a 1% reduction. Its 2020 EPS outlook was cut to to $176 from $180, marking a 2% reduction. That places the firm's outlook below Wall Street's consensus for this year and next.

"Our downward revisions are mainly driven by sectors that are directly hit by the recent trade tensions," they wrote, pointing specifically to industrials and materials.

"The trade war is likely to become increasingly visible in the inflation numbers," Goldman Sachs US economists led by Hatzius wrote in a Sunday note.

On the heels of the newly announced tariffs on all Mexican goods, Goldman's new US core PCE forecast — the personal consumption expenditure, a measure of the change in prices in goods and services — rises to 2% in August. It was at 1.57% in April.

That measure could then jump to between 2.3% and 2.4% in early 2020 before falling under the assumption that tariffs will be removed, the economists said.

"If all proposed tariffs are implemented, we estimate a core inflation impulse that peaks at an eye-popping +1.25pp early next year," they wrote.

"The unpredictability of the administration regarding tariffs/trade combined with a late cycle economy and a Fed seemingly on hold makes a 16x multiple now unreasonable, and 15x seems much more appropriate," Tom Essaye, the founder of the Sevens Research Report newsletter, said in a Friday note to clients.

With that earnings multiple and a 2020 S&P 500 EPS forecast of $180, a "reasonable downside target" is now 2,700, Essaye wrote. That implies a drop of about 3% off current levels.

At the same time, there are "real doubts" over whether that $180 estimate can even hold up, particularly if the international-trade conflict deepens, he said.

Stocks plunged Friday on the heels of Trump's announcement, and have since recovered their losses. US equity markets on Tuesday were firmly in positive territory, with the Dow Jones Industrial Average up more than 400 points.