Among the distinctions of John McCain's political life was being targeted by one of the ugliest smear campaigns in memory.

Now, courtesy of Republican operatives tied to House Speaker Paul Ryan, a Democratic House candidate is giving the late Arizona senator competition even as the nation mourns him.

For McCain, it was flyers and phone calls to South Carolina voters suggesting he fathered a dark-skinned child whom he and his wife Cindy actually adopted from Bangladesh after she was orphaned. For Abigail Spanberger, it is a groundless suggestion of ties to terrorism when actually she spent eight years as a CIA counterterrorism agent.

The attack on Spanberger, now challenging GOP Rep. Dave Brat in Virginia's 7th District, involved three extraordinary steps.

The first appeared to start with routine opposition research. A Republican consulting firm asked the government for Spanberger's personnel records under the Freedom of Information Act.

What came back three weeks later was anything but routine: Spanberger's highly confidential application for a security clearance to work at the CIA. Such "SF-86" applications are strictly shielded by privacy rules.

The Republican firm says it got the form by mistake from the Postal Service, where Spanberger once worked as a postal inspector. The Postal Service on Thursday apologized for its "human error."

That doesn't explain how a mistake of that magnitude occurred so rapidly. Spanberger requested her own personnel records months ago and hasn't received them.

The second step was equally remarkable. Instead of returning the document, the research firm gave it to the Ryan-linked super PAC, the Congressional Leadership Fund.

Seeking political advantage, the fund gave it to an Associated Press reporter in hopes of drawing attention to one tidbit: at age 23, while awaiting her security clearance, Spanberger taught English at an Islamic school in suburban Washington. A graduate from before Spanberger worked there later was convicted of assisting al-Qaeda.

Wary of how Republicans obtained the form, the AP didn't publish a story. Suggestions of impropriety were self-negating anyway, since the teaching stint occurred during an active federal background check that approved Spanberger for top-secret work.

That made the third step so audacious. Once a New York Times story publicized the form's improper release, the Ryan-linked PAC embraced the innuendo rather than renouncing it.

"It should surprise no one that Ms. Spanberger would want to hide from voters that she worked at a school that produced some of the world's most dangerous terrorists," the fund declared.

The PAC offers no evidence Spanberger did anything wrong. Unless it can, the attack is a stone-cold smear.

Outraged Democrats, fearing other candidates remain at risk, have demanded a federal investigation. Without elaboration, the Postal Service says "a small number of additional requests for information from personnel files were improperly processed."

Ryan distanced himself from the episode, with a spokesman insisting "we cannot speak to the activity or behavior of outside groups." So did House GOP campaign chief Steve Stivers, whose spokesman said it "has nothing to do with us."

Brat, an economics professor who might be expected to campaign on tax cuts and growth, hasn't commented.

But prominent Republicans outside the party's fight to hold its House majority share the Democrats' outrage.