> For example can Trump ask IRS to target say H1B employees ?
I anal but my guess is no, at least not as an order, and at least not in a way that is consistent with our laws.
> In 2013, the United States Internal Revenue Service (IRS) revealed that it had selected political groups applying for tax-exempt status for intensive scrutiny based on their names or political themes. This led to wide condemnation of the agency and triggered several investigations, including a Federal Bureau of Investigation (FBI) criminal probe ordered by United States Attorney General Eric Holder.
https://en.wikipedia.org/wiki/IRS_targeting_controversy
However, sitting senators and representatives can write letters to the IRS or any federal agency and my understanding is the people at the federal agency actually read those letters.
Here's just an example I found on Google search
> Senate Finance Committee Ranking Member Sen. Ron Wyden, D-Ore., and House Ways and Means Ranking Member Rep. Richard Neal, D-Mass., today questioned whether the Trump administration is wrongfully pressuring the IRS to produce 2018 withholding tables that would result in systematic underwithholding of federal taxes from taxpayer earnings. In a letter to Acting IRS Commissioner and Assistant Secretary for Tax Policy David Kautter, Wyden and Neal asked about interactions between Trump officials and the IRS regarding the development of the tables, which are expected to be released in the near future. If an undue amount of taxes are underwithheld by employers now, millions of hardworking Americans will owe taxes next April instead of receiving a tax refund.
https://www.finance.senate.gov/imo/media/doc/010818%20IRS%20...
https://www.finance.senate.gov/ranking-members-news/wyden-ne...