(Sorry Peter) You know that when Democrats start quoting Ronald Reagan something’s up. What the Berlin Wall has to do with stopping Mexican illegal immigration, I don’t know, but the Democrats seemed to think there’s a connection during the floor debate on extending the triple fence, which was approved last night. Defensive walls and fencing can be very effective — as the Moroccans found in Western Sahara, as the Israelis have found in Gaza and Judea and Samaria, as Hadrian found in Scotland — so long as they’re part of a broader effort at border enforcement. Opposing them in principle, as many of the Democrats are doing, is proof of frivolousness.