Even distinguished former Foreign Secretaries such as Jack Straw and Sir Malcolm Rifkind might be forgiven for having forgotten the Treaty of Guadelupe-Hidalgo. But it determined that California would be part of the United States rather than a province of  Mexico. Nicholas Trist was the lead US negotiator  and he believed he had not been properly recompensed for his services – which do, in retrospect, seem to have been considerable.  After a twenty year campaign, he hired a Boston lawyer, Linus Child, to lobby Congress on his behalf.

Child’s efforts bore fruit.  His son told Mr Trist that ‘everything looks very favourable.  I find that my father has spoken to C and B and other members of the House. ….. Every vote tells, and a simple request to a member may secure his vote, he not caring anything about it’.   Congress agreed to pay Trist $15,000, a considerable sum in those days.

Trist, always a hard bargainer, refused to pay Child’s son – Linus had by then died – the  contingency fee he had agreed, The case went to the Supreme Court, which dismissed Child’s claim. A contract to lobby government was contrary to public policy and hence  – like an agreement to supply sexual services,  unenforceable in the courts,   

      Paid lobbying, said Mr Justice Swayne, was ‘pernicious in its character’. But this was only the beginning of his denunciation.  ‘If any of the great corporations of the country were to hire adventurers to procure the passage of a general law with a view to the promotion of their private interests, the moral sense of every right-minded man would instinctively denounce the employer and employed as steeped in corruption and the employment as infamous.’ What would Justice Swayne have thought if he walked down K Street today?

The twentieth century eroded this austere view of the proprieties of political life. – if not necessarily the grubby everyday reality. But the notion that politicians might themselves become professional lobbyists  after leaving office remained unacceptable. When Harry S Truman ceased to be President of the United States in 1953, he determined, according to biographer David McCulloch, that ‘his name was not for sale.  He would take no fees for commercial endorsements, or for lobbying or writing letters or making phone calls’. Truman had little personal wealth and had earned only modest public salaries , and the embarrassment of his poverty  led Congress to make financial provision for America’s former Presidents.

But by the time of Bill Clinton’s retirement, this pension and contribution to office costs was hardly necessary.  The great corporations of the day did not hesitate to hire ‘adventurers who made markets of themselves ’, and it was common for members of Congress to leave office in order to swell their numbers. Prime Ministers and Presidents could expect to become millionaires on leaving office, and lesser politicians sold access to their contact books for sums far in excess of what they had earned in public service.

       The Court of the 1870’s had taken the view that free speech and honest speech were two sides of the same coin. ‘The theory of our government’, ruled Swayne, ‘is that all public stations are trusts’.  There was a corresponding duty on the citizen. ‘In his intercourse with those in authority, he is bound to exhibit truth, frankness and integrity’.

 But in Citizens United in 2010, the same Court held that the expression of views you were paid to hold was no longer ‘an infamous employment, steeped in corruption’, but an activity deserving of the protection awarded to free speech under the First Amendment.

But was Justice Swayne perhaps right to predict that ‘ if the instances (of paid lobbying) were numerous, open, and tolerated, they would be regarded as measuring the decay of the public morals and the degeneracy of the times’?