The Republicans must maintain that so long as there is a plausible foreign policy objective connected with the president's interaction with a foreign power, he is immune from being called to account in Congress for collaterally benefiting himself personally or politically.
Stop acceding to this extraconstitutional "quid pro quo" test. It distorts the Constitution and invades the separation of powers.
Until this is done opportunists like Mitt Romney can intrude into our foreign affairs at their whim.
A foreign official would have to be out of their mind to speak to a US president in confidence now.