Kempe had a prominent position in the English council as a supporter of Henry Beaufort, whom he succeeded as chancellor in March 1426.
Kempe held office as chancellor for six years; his main task in government was to keep Humphrey of Gloucester in check.
He supported Suffolk over the king's marriage with Margaret of Anjou; but afterwards there arose some difference between them, due in part to a dispute about the nomination of the cardinal's nephew, Thomas Kempe, to the bishopric of London.
At the time of Suffolk's fall in January 1450 Kempe once more became chancellor.
As Richard of York gained influence, Kempe became unpopular; men called him "the cursed cardinal," and his fall seemed imminent when he died suddenly on the 22nd of March 1454.
