First of all, as so commonly happens when Democrats try to pull off another anti-Trump coup, the entire definition of this issue has become distorted to how they wish it to appear. The President of the United States is required to investigate whether foreign countries seeking US aid are involved in corruption, to insure that the aid is properly used. That aid is supposed to be withheld if corruption is found. There was no need for Trump to inquire about corruption as pertaining to then Vice-President Joe Biden (who openly broadcasted it on video). Clearly, there was corruption pertaining to Hunter Biden, who brought nothing to the Burisma table other than being the son of the US Vice-President. Maybe Trump was wrong to allow Ukraine to get the aid they got, as was Obama who also gave Ukraine aid (although he did withhold MILITARY aid, and just gave blankets). By giving aid in the face of the Biden/Burisma corruption, the Ukrainians now become comfortable in engaging in corruption, while requesting US aid.