Credit to Matthew Yglesias for his discussion of the incompetence of Donald Trump as well as the excuses for it from his defenders including:
Officials have also cited the Posse Comitatus Act as a complicating factor that helps explain why Trump was so much slower to dispatch assistance to Puerto Rico than the Obama administration was to send help to Haiti after it was devastated by an earthquake in 2010.
Except this 1878 Congressional Act does not bar the President from calling in the military as Michael Spak and Donald Spak note:
Before 1878, it was common for the United States Army to enforce civilian laws. In frontier territories, the army was often the only source of law enforcement, supplemented by occasional U.S. Marshals. Over time, marshals and county sheriffs regularly called upon the army to assist in enforcing the laws… By the time of the 1876 presidential election, Southern states were reconstituted. Many Southerners opposed both Grant, the outgoing Republican president, and Rutherford B. Hayes, the Republican presidential candidate. Federal troops actively assisted U.S. Marshals in patrolling and monitoring polling places in the South, claiming to be enforcing the federal election laws and preventing former Confederate officers from voting (as was the law at that time). Following bitter election contests in four Southern states, Hayes won the presidency by one electoral vote. Many felt that the federal troops, which supported Hayes and the Reconstructionist Republican candidates for Congress, intimidated Southerners who would have voted for Samuel Tilden, the Democratic candidate. The resulting Democratic Congress was at odds with the Republican President Hayes. In response to what was seen as undue influence over the 1876 election, Congress outlawed the practice of posse comitatus by enacting the Posse Comitatus Act (PCA) (as 20 Stat. 152) as a rider to the Army Appropriation Act for 1880. The act stated: “Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.” Congressional debates indicate that the PCA was intended to stop army troops from answering the call of a marshal to perform direct law enforcement duties and aid in execution of the law. Further legislative history indicates that the more immediate objective was to put an end to the use of federal troops to police elections in ex-Confederate states where civil power had been reestablished.
In other words, this PCA is an outdated piece of legislation. But there’s more:
Others suggest the act is obsolete and should be repealed because numerous legislative exemptions have eroded the underlying policy and left the PCA a hollow shell. Others insist that although there are many exceptions, the act is essential to bar misuse of the military by civilian authorities and to prevent a military dictatorship from assuming control of the nation through use of the armed forces. Still others argue that the act means only that federal military forces may not be commandeered by civilian authorities for use in active and direct law enforcement as a posse comitatus. If local authorities need military personnel for specialized operations enforcing state laws, it is argued, they may call on the state governor for the assistance of the state National Guard.
There are many exceptions and no one would think giving aid in a time of need endangers either military dictatorship or the misuse of the military by civilian authorities. This pathetic excuse from Team Trump is just another example of how he turns everything into a culture war.