While the focus for US President Donald Trump during the Iran war is naturally on avoiding human casualties, what he also needs to consider is the damaging impact it is having on the Republican Party. Without Republican control of the House and the Senate, many of his programs will be reversed and he will struggle to achieve his goals. It could even end his presidency. It is almost certain that a Democratic-controlled House would impeach the president, although it would take a significant loss in the Senate to take that further.