Billionaire Republican megadonor Harlan R. Crow gave the maximum allowed contribution to the campaign for Sen. John Fetterman, D-Pa., according to a new filing with the Federal Election Commission on Wednesday.

Crow — magnate of a Texas real estate empire, longtime Republican donor, and past dual citizen of St. Kitts and Nevis — has come under increased scrutiny in recent years after ProPublica reported that he financed luxury travel for and bought property from conservative Supreme Court Justice Clarence Thomas, who did not disclose the dealings. Crow also reportedly paid tuition for Thomas’s grandnephew at a private boarding school in Georgia.

Crow did not immediately respond to a request for comment about the contribution to Fetterman’s campaign.

Fetterman has drawn ire from his previous supporters and Democratic colleagues for what they’ve characterized as a stark shift in his ideological and policy stances since he was first elected to the Senate. That shift has attracted Republican donors who said they appreciated Fetterman’s vocal embrace of pro-Israel policies since entering office. A recent poll found that a majority of Democrats in Pennsylvania want Fetterman to leave the party, and that his approval rating is higher among Republicans than Democrats. Last week, Fetterman launched a bipartisan joint fundraising committee with Sen. Dave McCormick, R-Pa.