What can happen if Trump is removed (1)?

Financial markets have experienced a difficult Friday last week. The leading US indices dropped momentarily after it became clear that Michael Flynn admitted he had lied in the testimony given to the FBI and could provide new evidence of inappropriate relations between President Trump and Russia.
What could happen?
The chances for President Trump to step down from his post are rising. This could be the worst scenario for investors because it would lead to serious political uncertainty at a time when stock prices rose seriously in anticipation of Trump's tax reform. The latter, however, is delayed and there are serious chances not to become a reality since the beginning of next year, as were the real expectations of investors.
There is a real opportunity for Washington to turn to its biggest crisis since the Watergate scandal in the early 1970s. At the same time, when Trump is removed, he is expected to be replaced by current Vice President Mike Pens, who would become premature the 46th US president.
And while this still seems like a fairly unlikely scenario, more and more investors are beginning to wonder, what would President Pens mean for the US stock markets?