Which U.S. President, despite facing significant political opposition and a near-impeachment, oversaw a period of economic prosperity and normalized relations with a major communist nation?

1. He was a prominent figure in the Watergate scandal, though he maintained his innocence.
2. He served as Vice President before assuming the presidency.
3. His presidency is often associated with the phrase 'Whip Inflation Now'.
4. He controversially pardoned his predecessor to heal the nation.