President Obama is set to tweak a few words in the federal workforce nondiscrimination order to explicitly prevent federal contractors from discriminating on the basis of sexual orientation or gender identity.

Significantly, Obama's changes don't provide any exemption for religiously-affiliated contractors, such as faith-based social services, making them subject to the same rules as other contractors. Religious contractors can, however, continue to prioritize hiring members of a particular faith.

The universe of workers potentially affected by the order is at once wide-reaching and narrow. "Obama’s executive order will apply to the 24,000 companies designated as federal contractors whose 28 million workers make up a fifth of the country’s workforce," writes Jonathan Capeheart. On the other hand, 92 percent of the largest contractors already have some sort of protection for sexual identity, and 58 percent already have protection based on gender identity.

The measure is also both narrower and more wide-ranging than the Employment Non-Discrimination Act, which was passed by the Senate but is dead in the House. Narrower because ENDA would have applied to all workers, not just federal contractors; and more wide-ranging because ENDA did include a religious exemption.

Measures like this one are hardly controversial among the general public. More than 7 in 10 Americans favor laws protecting gays and lesbians from workplace discrimination, according to the Public Religion Research Institute. And three-quarters think that such discrimination is already illegal under federal law (it's not).

To the extent that the measure is at all controversial it will be because of the lack of religious exemption. Obama likely wants to avoid another situation like the recent Hobby Lobby case, in which the Supreme Court ruled that the federal government can't force private, closely-held businesses to provide birth control as part of their health care plans if they object to it on religious grounds. By not providing a religious exemption in this order, Obama is aiming to remove those grounds completely, at least from a legal standpoint.

Symbolically the order is a big victory for LGBT advocates. But it's also a reminder that in 2014, political change is largely confined to the margins of any given issue. The order will really only change the hiring landscape for the small fraction of federal contractors who previously would have discriminated against LGBT workers on grounds religious or otherwise.