California Gov. Gray Davis hasn't been able to draw 50 percent of the electorate in election polling, but he still has a double-digit lead over his Republican challenger in the state's gubernatorial race.

According to a recent San-Francisco-based Field Institute poll, 43 percent of the 546 voters surveyed would vote for Davis if the election were held today. On the contrary, 29 percent would vote for Bill Simon, a businessman who unexpectedly was swept to victory against former Los Angeles mayor Richard Riordan and Secretary of State Bill Jones in the March 5 Republican primary.

The telephone survey, taken between April 19-25, has a 4.5 percent margin of error and represents a shift from two months ago when Simon held a slight lead over Davis in statewide surveys.

Simon, whose late father served as treasury secretary under Presidents Ford and Nixon, is a multimillionaire who has refused to turn over his personal income taxes. About half of voters polled said they agreed that Simon is not obligated to do so.

The political newcomer was hoping to turn those numbers around with a visit from President Bush Monday. Bush was appearing at a fund-raiser expected to raise $2.5 million for Simon.  Bush backed Riordan in the primary, but after Simon's win, said he would do what he could to help the upstart defeat Davis.

The Associated Press contributed to this report.