Carly Fiorina has pulled even with former Rep. Tom Campbell in the race for the Republican Senate nomination, according to a new poll, but many primary voters are still making up their minds.

The survey, conducted March 9-16 by the Public Policy Institute of California, found Fiorina leading Campbell 24 percent to 23 percent among Republican primary voters, making the two leaders statistically tied.

Assemblyman Chuck DeVore was well behind with only 8 percent; 44 percent were undecided. PPIC surveyed 410 Republicans for its poll, which had a 5-point margin of error.

PPIC’s findings are at odds with a Field Poll conducted over the same time period.

The Field Poll, released earlier, found Campbell leading Fiorina 28 percent to 22 percent with DeVore at 9 percent.

Both polls, however, show the primary race has tightened since Campbell joined the field in January.

Spokeswoman Julie Soderlund said Fiorina would continue to build on the 12-point gain since the January PPIC poll.

“As the choices in this race become clearer, Carly is the best candidate to take on” Sen. Barbara Boxer (D), Soderlund said. “This is an encouraging trend that we expect to continue throughout the primary.”

DeVore got some positive news when he was endorsed by one of the leaders of the conservative wing of House Republicans, Rep. Jeff Flake (Ariz.).

Flake said in a statement that he’s backing DeVore because “he won’t bend with the political winds: he’ll stay true to the convictions that have guided him throughout his public career.”