Former U.S. Secretary of State Condoleezza Rice hits her approach shot on the ninth hole during the second round of the Pebble Beach National Pro-Am golf tournament in Pebble Beach, California February 13, 2015. REUTERS/Michael Fiala

(Reuters) - Former U.S. Secretary of State Condoleezza Rice polled at the head of a crowded pool of potential candidates to succeed long-time Senator Barbara Boxer, according to a Field Poll released on Wednesday.

The poll showed that when likely California voters were asked whether they would vote for or against 18 prominent possible candidates in 2016, 49 percent of likely California voters said they would be inclined to support Rice, a Republican.

Rice’s support was significantly stronger among likely Republican voters, with almost three-quarters saying they would back her. The next closest Republican candidate, former State Senator Phil Wyman, saw only 51 percent support from Republicans.

California Attorney General Kamala Harris, who is a Democrat and the only person listed in the poll who has formally announced they are running, saw the most support of any Democrat, with about three-quarters of likely voters in her party saying they would back her.

She was second to Rice overall, drawing support from 46 percent of those polled.

Hispanic voters rallied behind former Los Angeles Mayor Antonio Villaraigosa, with 60 percent saying they would back the Democrat, though he trailed Harris among all poll-takers in his party by nearly 20 percentage points.

Boxer’s departure is the first of three anticipated retirements among California’s top leaders that should clear the way for a younger generation of politicians.

Governor Jerry Brown, 76, will leave office at the end of his fourth term in 2018 because of term limits. U.S. Senator Dianne Feinstein, 81, will be 85 when her term ends.

The poll surveyed 972 likely voters in California, broken into two groups, from late January to mid-February by phone. The results from both groupings have a sampling error of plus or minus 4.5 percentage points.