Washington (AFP) – As President Donald Trump prepares to leave office, he is highlighting the same issue that helped get him elected in the first place: the US-Mexico border wall. Trump visited Texas on Tuesday to tout the completion of more than 450 miles (700 kilometers) of new wall and barrier improvements under his administration. The White House has boasted the achievement marks a “promise made, promise kept” — but the reality is more nuanced. Campaign promiseAs he launched his presidential campaign in 2015, Trump promised: “I will build a great, great wall on our southern border, and I …