Equifax’s Huge Breach Tests Trump Pledge to Dismantle Rules

The massive Equifax Inc. data breach has triggered demands on Capitol Hill for stiffer rules and new requirements for what financial companies must do to fend off cyberattacks.

Yet tougher oversight would all but certainly require support from the Trump administration and buy-in from congressional Republicans -- both of whom want to reduce financial regulation not stiffen it. Democrats so far have led the calls for more rules in the wake of Equifax’s disclosure that 143 million Americans’ personal information was stolen.

Tighter constraints would pose a particularly difficult choice for GOP lawmakers because it would most likely mean further ...