James McCulloch most likely supported the idea that Congress could create banks because

he knew that Maryland law did not allow for state-run banks.

he believed the Court should follow the implied powers of the Constitution.

he supported the idea of federal supremacy.

he didn't want to pay state taxes on his bank.

The right answer is D "he didn't want to pay state taxes on his bank."

Explanation:

Before this episode happens, banks in Maryland had a law that said that federal banks were required to pay state taxes. James McCullock thought that the Congress could be able to create banks because he did not want to pay state taxes in his own bank. After the court, the Supreme court gave the Congress the power to create a federal bank with the power of absorb debts of the war and create a national currency.