U.S. President Donald Trump listens to question from the media on South Lawn of the White House in Washington, U.S., before his departure to visit the FBI Academy in Quantico, Virginia, U.S. December 15, 2017. REUTERS/Yuri Gripas

The FBI Agents Association (FBIAA) reported a "significant uptick" in the number of donations it received in December compared to the same time last year, according to spokesman Paul Nathanson, amid President Donald Trump's repeated efforts to undermine public confidence in the bureau.

"This month, more than 2,000 donors contributed over $140,000 to our two charitable funds," FBIAA spokesman Paul Nathanson said in an email. "I can say that it's a significant uptick in the number of donors and donations that we typically receive in December."

Nathanson said the donations "will be used to support the two FBI Agents Association charities: The Memorial College Fund, which sends children of deceased Agents to college. And the Membership Assistance Fun, which helps Agents and families facing hardship or tragedy."

Over the past month, Trump has tweeted that the bureau's reputation is "in tatters," attacked the FBI's deputy director, Andrew McCabe, and taken a swipe at the FBI's top lawyer, James Baker.

Following Trump's attacks, Lawfare editor-in-chief Ben Wittes started the hashtag #thanksFBI and urged his 214,000 Twitter followers to donate to the FBIAA, which says its mission "is to advance & safeguard the careers, economic interests, conditions of employment and welfare" of current and former FBI agents.

"The President is impugning the integrity of the FBI by attacking two honorable public servants: Jim Baker and Andy McCabe," Wittes wrote on December 23. "I just donated $1,000 to the @FBIAgentsAssoc in their names. I urge others to give as well and tweet that you did so to #thanksFBI."

Several high-profile former intelligence and national-security officials followed suit, including former CIA Director John Brennan and former Homeland Security adviser Lisa Monaco.

"Andy McCabe & Jim Baker epitomize integrity, competence, and respect for rule of law," Brennan tweeted last weekend.

"Not surprised @realDonaldTrump fears them, along with the rest of FBI. I just donated to @FBIAgentsAssoc as a small way of saying #thanksFBI. Here's how you can too: https://fbiaa.org/ways-to-donate."

Dozens of Twitter users then screenshot their FBIAA donations, most of which were made in McCabe and Baker's names.

'Anyone can be attacked for partisan gain'

In another sign of its rising profile, the FBIAA gained approximately 15,000 Twitter followers this month alone. It started December with just over 1,000 followers.