Because if they stayed too long, they'd be subject to pressures from lobbyists and would lose an independent sheen. And I wouldn't have them coming in with a new government for the same reason, a second chamber wouldn't be too associated with one party,
People also have lives to get back to...
I've long been for the idea that our second chamber shouldn't be elected or selected but should comprise 200 people, selected randomly across the country but no-one who's a member of a political party or who works for a think-tank or as a SPAD would be eligible to stand. Everyone serves for two...