According to the Article II, Section 2 of the constitution laid out the of the executive arm and it powers( the president to be precise)
"He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein other- wise provided for, and which shall be established by Law..."
The article provision for the congress "The section also provides that Congress may vest the appointment of inferior officers in the President alone, in the courts of law..."
Furthermost, the separation of power in the constitution says the congress may not vest itself any broader appointment powers than what is provided for by the constitution.
For the congress to reject the nomination of this aging industrialist, the congress must vest the appointment in the court of law or the heads of department as provided in the constitution, without this step , they are not permitted to resist the candidate nominated and this action is the violation of the separation of powers according to Article II, Section 2