The bank lobby is making another attempt to unseat Rep. Walter Jones, R-N.C., the maverick House Republican who consistently supported greater oversight of the finance industry, and is the last remaining member of the GOP caucus to have voted in favor of the Dodd-Frank reform law.

The American Bankers Association, a lobby group for the banking industry, this week used a subsidiary called the Fund for Economic Growth to pour $50,000 into campaign advertisements in support of Taylor Griffin, a candidate seeking to unseat Jones in the Republican primary on June 7.

This is the second attempt by Griffin. In 2014, Griffin left a position with Hamilton Place Strategies, a consultancy that helps Wall Street firms with political strategy, to challenge Jones. Griffin’s bid was backed by a Super PAC funded by hedge-fund manager Paul Singer, as well as funds from many major corporate political action committees, particularly from big banks such as Wells Fargo and J.P. Morgan Chase.

Despite well-heeled support from the establishment, Griffin lost.

Campaign finance records show that banks are again fueling his primary challenge this year. PACs controlled by J.P. Morgan Chase, Goldman Sachs, Bank of America and Wells Fargo have contributed to Griffin’s campaign, according to Federal Election Commission disclosures. So, too, has the American Bankers Association’s PAC, which provided the maximum donation of $5,000. Thanks to the Citizens United Supreme Court decision, however, the ABA is allowed to exceed the traditional campaign donation limit by using a corporate subsidiary to spend $50,000 in support of Griffin’s campaign as an independent expenditure.

“Griffin has the experience and expertise to advocate for pro-growth economic policies in Congress that will foster job creation,” says Elizabeth Colt, a spokesperson for the American Banking Association’s FEG. “He is a proven leader with principled values.”

Jones has bucked the demands of Wall Street by opposing a number of proposals to deregulate big banks, and was the only House Republican to reject an effort last year to delay the implementation of the Volcker Rule, which bans taxpayer-backed banks from speculative trading.

Ethics records show Griffin has taken up work as a consultant to the health insurance industry, providing public relations advice over the last year to Aetna, Amerihealth, Anthem, UnitedHealth Group, Centene Corp, and Wellcare Health Plans.

Jones has also earned the ire of powerful conservative and business interest groups for criticizing the wars in Iraq and Afghanistan, for backing campaign finance reform, and for loudly condemning House Republican leadership for having cozy ties to lobbyists. Along with Rep. Stephen Lynch, D-Mass., Jones was among the very first members of Congress to call for the release of the 28 pages of the 9/11 Commission Report, the classified section that reportedly details Saudi Arabian support for the September 11 attack.