The House is poised to pass tax reform on Thursday, while Senate Republicans have fortified their draft to include a repeal of ObamaCare’s individual mandate. The latter is being denounced as an attempt to deny Americans health insurance, but Republicans can rebut this falsehood and achieve two policy goals with one reform if they don’t flinch from the debate.

Republicans are right to want to repeal the mandate that fines Americans who don’t buy health insurance. Their dual motive is to repeal the most loathed part of the...