After being forced from Goldman Sachs in January 1999, Corzine campaigned for one of New Jersey's Senate seats after Frank Lautenberg announced his retirement. Corzine was elected to the Senate by a four percent margin over his Republican opponent Bob Franks in the November 2000 election and was sworn into the Senate in January 2001. He spent over $62 million of his own money on his campaign, the most expensive Senate campaign in U.S. history - over $33 million of this was spent on the primary election alone, where he defeated former Governor James Florio 58%-42%

Corzine's candidacy for Governor, like his prior run for the U.S. Senate, broke all prior spending records. The combined expenditures for Corzine's run for the Senate and Governorship exceeded $100 million.

Corzine won his campaign for the post of Governor of New Jersey with 54% of the vote. Republican nominee Doug Forrester, a businessman and a former Mayor of West Windsor Township, in Mercer County, won 43%. Corzine received 1,224,493 votes to Forrester's 985,235. A total of 80,277 votes, or 3%, were scattered among other candidates.