Readying to resign his Congressional post amid fresh sexual misconduct allegations and broader questions about his psychological fitness, Rep. David Wu’s plummeting political fortune has become a liability for those Democratic lawmakers whose campaign coffers were filled years past by donations from the Oregonian and his leadership fund.

The National Republican Senatorial Committee highlighted on Tuesday a series of Wu’s yet-returned campaign donations to Democratic Senate hopefuls Chris Murphy and Tammy Baldwin.

NRSC aides circulated comments to regional press explicitly wondering if the pair’s silence was an indication they “want[ed] to keep the campaign contributions … received from Wu.”

The seven-term Oregonian donated $1,000 to Rep. Chris Murphy’s 2006 House bid and $3,000 to Rep. Tammy Baldwin’s House campaigns in 2000 and 2002. Both lawmakers have yet to return the contributions or publicly comment on the allegations facing Wu.

“Given the very serious nature of the allegations against Congressman Wu, and his support for Tammy Baldwin’s political career, isn’t it time for Congresswoman Baldwin to return the money Wu gave to her campaign,” NRSC spox Chris Bond asked. He provided a similar statement on Murphy’s likewise buttoned lip.

Wu, who faced an inquiry from the House Ethics Committee, announced yesterday he would leave Congress.