Why did Trump pick Amy Coney Barrett for Ginsburg's Supreme Court seat?

US President Donald Trump has nominated conservative federal judge Amy Coney Barrett to succeed Supreme Court Justice Ruth Bader Ginsburg.

If confirmed by the Republican-controlled Senate, Trump will have put three of the nine justices on the top court, possibly handing conservatives long-sought wins over contentious legal issues such as abortion and gun rights.

So who is Amy Coney Barrett, and could her nomination have an effect on the 2020 election?