He won the seat at a by-election following the death of the former Liberal leader Clement Davies and retained it through five general elections. The Shropshire Star has a photograph of him being carried through the streets of Welshpool after the constituency's result was declared in October 1974 election.
As his Daily Telegraph obituary makes clear, he was not afraid of controversy:
After Liberal losses in the 1970 election, Hooson told the Liberal Assembly that the public wanted a middle-of-the-road party, blaming Jo Grimond and Jeremy Thorpe for trying to take it Leftward. When the Liberals merged with the SDP in 1988, he backed Alan Beith for the leadership against the less cautious Paddy Ashdown.
Hooson attracted abuse from party activists, particularly the Young Liberals who at one conference waved sticks of rhubarb at him when he opposed sanctions on South Africa. Yet they were allies in opposing the Vietnam War, and the Young Liberals’ leader, Peter Hain, relied on Hooson’s advice when forced to apologise to Edward Short, Leader of the Commons, for suggesting he was implicated in the Poulson affair.
Hooson opposed both Grimond’s readiness to keep the 1964 Labour government in power, and the Lib-Lab Pact concluded with James Callaghan by Steel. But the leader he trusted least was Jeremy Thorpe. When Grimond retired in 1967, Hooson stood against Thorpe partly on policy grounds but also because of a deep and, as events would prove, shrewd distrust of Thorpe’s character.He also enjoyed a distinguished legal career. The Telegraph says:
Hooson also enjoyed a distinguished legal career At the Bar, Hooson earned a reputation as a cool, clear thinker and lucid advocate. In 1960, at 35, he became the youngest Silk for many years.Hooson defended Ian Brady in the Moors Murder trial and, so Disgruntled Radical always tells me, prosecuted Alan Turing when he was tried for 'indecency'.