evidence: It has been widely suggested that the DUP and others are misconceived (or worse) in their opposition to the backstop laid out in a protocol to the Withdrawal Agreement agreed by negotiators in November last year. What’s the big problem with "extra checks at Northern Ireland’s seaports and airports" asked David Green in a Spectator blog. [...] For Northern Ireland this is particularly sensitive and supporters of the Union are concerned that under the backstop the Irish government would effectively have more say over some issues than either the Westminster government or any government in Stormont would have. [...] Critics of the backstop could ask how, if a joint committee can be tasked to deliver solutions to avert a hard border between Great Britain and Northern Ireland during the transition period, why such commitments could not be deployed instead to the land border, where after all there are already trade frictions and formalities associated with VAT, excise duty, currency exchange and regulatory differences.