The Corzine challenge: can he do better against Ken Balut than Dick Hughes did against Bill Clark?

Only twice have incumbent statewide officeholders lost primary elections.  They were both Republicans: in 1973, U.S. Rep. Charles Sandman defeated Governor William Cahill by a 58%-41% margin; and in 1978, when four-term U.S. Senator Clifford Case lost to Jeffrey Bell, a 35-year-old former speechwriter for Ronald Reagan, by a 51%-49% margin.

In 1977, Governor Brendan Byrne had ten opponents in the Democratic primary, including two Congressmen, a State Senator, and his own Commissioner of Labor.  Byrne won with 30% of the vote; U.S. Rep. Robert Roe came in second with 23%.

The most high profile primary against an incumbent came in 2008, when 84-year-old U.S. Senator Frank Lautenberg faced a major challenge from U.S. Rep. Robert Andrews.  Lautenberg won 59% of the vote in the Democratic primary, with 35% for Andrews and 6% for Morristown Mayor Donald Cresitello. 

Lautenberg has faced two minor challenges as an incumbent.  He won 81% against Bill Campbell and Lynne Speed in 1994 and 80% against Elnardo Webster (the father of a powerful Democratic lawyer) and Harold Young in 1988.

Seeking re-election to his third term in the U.S. Senate, Harrison Williams had to first fend off a Democratic primary challenge from then-State Senator Frank Guarini.  Williams won 66%-34%.  Williams would later serve a federal prison sentence for his role in the ABSCAM scandal, while Guarini spent fourteen years in the U.S. House of Representatives.

In 1965, incumbent Governor Richard Hughes won 91% of the vote in the Democratic primary against William J. Clark of Newark, who was the first African American to run in a statewide primary election. Clark ran at Hughes from the left as a Labor Vanguard Democrat.

Governors Thomas Kean (1985) and Christine Todd Whitman (1997) were spared challenges in the Republican primaries when they ran for re-election, even though some conservative Republicans were critical of them.  Despite huge political problems, Governor Jim Florio did not attract any major opponents in the 1993 Democratic primary.  Indeed, he ran unopposed after postal worker John Budzash, who led the grass roots Hands Across New Jersey that opposed Florio's tax hikes, failed to get enough signatures to force a primary challenge. 

And no Democrat stepped up to take on U.S. Senator Robert Torricelli in the 2002 primary, despite the ethical charges against him.