Wearing a candidate's campaign pin is hardly out of the ordinary this election season. But doing it while conducting congressional oversight at a hearing where that candidate's conduct is front-and-center -- that's another matter.

Rep. Sheila Jackson Lee, D-Texas, raised eyebrows Wednesday when she showed up wearing a gold Hillary Clinton campaign pin to a House Judiciary Committee hearing dealing with the FBI probe regarding Clinton’s private email server.

The committee heard testimony from FBI Director James Comey on the agency’s decision not to pursue charges and a newly revealed set of controversial immunity deals given to Clinton’s staff.

Jackson Lee asked Comey questions while wearing the "H" campaign pin -- though the exchange left no doubt as to her leanings on the matter.

"[Republicans] want you to prosecute, or ask the DOJ to prosecute, Secretary Clinton regardless of the facts. So they’ve engaged in an almost daily ritual of holding hearings, desperately trying to tear down the investigation," she told Comey.

The House has guidelines restricting certain forms of campaign-related activity, but there is no apparent ban on wearing pins. However, while it is not unusual in the slightest for representatives to express their political beliefs on Capitol Hill, wearing campaign paraphernalia during an oversight hearing is more of a rarity.

Jackson Lee also was spotted wearing the pin on the House floor during the vote to override President Obama’s veto of a bill allowing 9/11 victims’ families to sue Saudi Arabia.

Jackson Lee’s expression of support for Clinton was noted on a pro-Donald Trump subreddit, /r/The_Donald, in a thread entitled “Don’t mind me, just doing my impartial oversight with my shiny gold H pin on.”

Jackson Lee’s office did not immediately return a request for comment from FoxNews.com.

Jackson Lee isn’t the only lawmaker to sport an "H" pin on the Hill. On Tuesday, Clinton’s running mate Sen. Tim Kaine, D-Va., arrived on the Senate floor wearing the lapel pin.

When alerted to it, he said he had forgotten to take it off.

FoxNews.com’s Adam Shaw and Fox News’ Chad Pergram contributed to this report.