Trump Says He Won’t Turn Over His Tax Returns. It’s Not Up To Him Anymore.
Congress has the authority to get anyone’s returns from the IRS.
Congress doesn't have the authority to riffle through people's private information. I realize that Democrats like to violate people's rights, but the courts will only allow the Democrats to have data that they have a good reason for accessing.
And even then, any Democrat who leaks private information can expect to see the inside of a prison cell.