Rep. Rodney Frelinghuysen (R-N.J.), a top House Republican, said Friday morning that he would vote against the GOP’s Obamacare replacement bill, known as “Trumpcare.”

Frelinghuysen’s opposition is significant not only because Republican leadership can only afford to lose 21 or 22 votes, but also because he is the chairman of the powerful House Appropriations Committee. Committee chairpersons typically vote in line with the House leadership – and indeed set the party line and help pull recalcitrant members on board.

“Seven years after enactment of Obamacare, I wanted to support legislation that made positive changes to rescue healthcare in America,” Frelinghuysen said in a statement.