The pro-Corbyn take on a new party/PLP split seems deeply muddled. The repeated charge that the SDP kept Thatcher in power, and that a new party could do the same for today's Tories, contains an unspoken admission that there *is* an electoral constituency for such a party. (1/?) Even if all of the new party's support came from 2017 Labour voters (a highly unlikely outcome) that would still indicate that a significant minority of Labour's base strongly favours a different leader and a more centre-left platform. (2/?)