It is incorrect and dangerous to equate tax loopholes with government spending.
The tax codes countless credits, deductions, and exclusions let people keep a portion of their earnings, provided they use the money how the government wants them to use it. Tax loopholes therefore have a lot in common with government spending: they give power to politicians, inhibit freedom, reduce economic output, unjustly enrich special-interest groups, et cetera.
But to call them tax expenditures or tax subsidies or backdoor spending in the tax code is to claim that when the government fails to take a dollar from you, it is spending that dollar. It implies that your dollar actually belongs to the government, which is graciously letting you keep it. And it implies that eliminating a tax loophole is not a tax increase, because that dollar already belonged to the government anyway. The government has simply decided to spend its money somewhere else.
When you hear a politician use the terms tax expenditure, tax subsidy, or backdoor spending in the tax code, beware. Hes about to raise your taxes.