Arkansas Republican Sen. Tom Cotton responded to New York Times columnist David Brooks over his claims that curbing mass immigration would cripple the U.S., tweeting that an influx of low-skilled labor hurts the employment prospects of young Americans, minorities, and established immigrants. Cotton has sponsored a bill cutting annual immigration flows into the U.S. by half, by limiting entry to 500,000 foreign workers each years. It’s a popular position for a wide swath of voters: 54 percent want immigration halved or reduced to zero, including 22 percent who want a total moratorium. That includes 68 percent of Republicans and 45...