Donald Trump may be the head of the Republican Party, but when it comes to the Senate, Majority Leader John Thune is still in charge.

Trump, who will attend lunch with Senate Republicans at the US Capitol on Wednesday, is growing tired of hearing “no” from the Senate leader as he pushes certain controversial priorities, according to people familiar with his thinking.

But Thune is sitting on as much support as any leader could with less than five months until the midterms, and is surrounded by some emboldened colleagues who are more willing than they have been in years to take on the Republican administration.