TIJUNA, Mexico (Reuters) — In the border cities between Mexico and the United States, many businesses have already felt the so-called “Trump effect.” The value of Mexico’s currency, the peso, has plunged further following a series of tweets and state ments by U.S. President Donald Trump, who threatened to impose tariffs on Mexican products and renegotiate North American Free Trade Agreement (NAFTA). That’s not good news for people like Eduardo Martinez, who runs a car lot […]