The remarks came after Manafort was indicted and jailed for witness tampering. Manafort was Trump’s campaign manager for 5 months, personally picked Pence as his running mate, and was part the transition team. Manafort has since been convicted of tax and bank fraud, stemming from his work as a lobbyist for Russian interests in Ukraine.

The New York Times – Paul Manafort, Trump’s Former Campaign Chairman, Guilty of 8 Counts
The Guardian – Paul Manafort: judge sends ex-Trump chair to jail for violating bail terms