(06-05) 21:16 PDT San Francisco -- The potentially dramatic effects of two landmark California voter-backed reform measures began to emerge Tuesday, as voters cast ballots in a primary election that could lead to a change in the state's legislative profile in Sacramento and Washington.
Democratic Sen. Dianne Feinstein, seeking her fourth full term, was clobbering her 23 opponents in early returns, with four times the votes of her nearest competitor.
But another longtime Bay Area-based legislator, Democratic Rep. Fortney "Pete" Stark of Fremont, was struggling in his bid for a 20th term. The 80-year-old incumbent held a slim lead in Alameda County's 15th Congressional District over 31-year-old county prosecutor Eric Swalwell.
Both Feinstein and Stark were heading for spots in the November general election in the inaugural run of the state's "top-two" primary system in which the two leading vote-getters in the primary advance to the fall ballot regardless of party affiliation. The idea was approved by state voters as Proposition 14 in 2010.
Early results indicated that dozens of contests for the House and Legislature could pit two people from the same party against each other in November.
New districts

Californians were also voting for the first time for candidates vying to represent legislative and congressional districts drawn up not by gerrymandering politicians or the courts, but by a citizens' commission. Stark was only one of several incumbents thought to be in danger of losing their jobs in redrawn districts.
Californians also voted on a ballot measure that would revise term limits for state legislators and an initiative to add $1 a pack to the cigarette tax for cancer research, which became the focus of a $47 million advertising barrage, fueled largely by tobacco companies, to defeat the measure. Both initiatives were leading in early returns.
No drama at top

The presidential primaries - marquee races in some years - were devoid of drama this time. Mitt Romney, who has already amassed more delegates than he needs for the Republican nomination, handily won the GOP primary against candidates who have given up their campaigns.
President Obama was unopposed on the Democratic ballot.
In the U.S Senate race, Feinstein held a commanding lead in a field of 24 candidates. Running second in early returns was Republican Elizabeth Emken of Danville, an autism activist who was endorsed by the state GOP.
Barely registering in early returns was Orly Taitz, a "birther" all but disowned by the GOP establishment.
Low turnout

The lack of suspense at the top of the ballot contributed to a dampening of voter turnout. The Field Poll estimated that only 35 percent of the state's registered voters would cast ballots in the election, which would be a record low for a presidential primary.
For one, the secretary of state's office also said a record percentage of voters, more than one in five, are now registered as unaffiliated with any political party.
National implications

The redrawn district boundaries and new top-two rule for the general election led some observers to suggest that the primary could be the first step in Democrats picking up one to six House seats.
That is potentially important for the party's "Drive for 25," the number of seats Democrats need to wrest from Republicans nationally to regain control of the chamber they lost in the 2010 election.
In the Bay Area, however, the changes put Stark, one of the state's senior Democrats, at risk. Early returns showed that the once-invincible liberal, who holds the record in the California delegation for his tenure in office - nearly 40 years - holding a surprisingly slim single digit lead over Swalwell, a Dublin City Council member and prosecutor running his first major race.
Should the results hold, the fall match-up could be explosive.
Primary gaffes