The correct answer is he vetoed legislation to restore National Bank.
John Tyer betrayed his Party after assuming the Presidency because he vetoed legislation to restore National Bank.
John Tyler (1790-1862) was a United States Military Captain, Representative, Governor, Vice president and the 10th President of the United States. He belonged to the Whig Party and became President when William Henry Harrison died of pneumonia.
President Tyler vetoed a bill to restore the National Bank of the United States, and in consequense, the Whig Party expelled him. One year later, the Whig Party tried to impeach him due to the vete of another Bill, but Tyler remained as a President.