ALBANY – Attorney General Eliot Spitzer has a sizable lead over Governor Pataki, according to a statewide poll of eligible voters released Tuesday.

The Siena College Research Institute poll of 621 registered voters indicated that Mr. Spitzer, the heavy favorite to win the Democratic Party’s nomination for governor in 2006, led Mr. Pataki by 51% to 35% in a hypothetical race for state’s top job. The three-term Republican incumbent has not said if he will run for re-election next year.

The poll did not show Mr. Spitzer to be invincible. New Yorkers favored Mayor Giuliani over the state’s current attorney general in a theoretical governor’s race, 49% to 40%.

Nevertheless, Mr. Giuliani trailed Hillary Rodham Clinton in a theoretical Senate race, 52% to 43%, the poll showed. Ms. Clinton was at one time thought to be an underdog against Mr. Giuliani in the 2000 race for the Senate, from which the then-mayor withdrew after he was diagnosed with prostate cancer.

The Siena poll gave Mrs. Clinton a huge margin over Mr. Pataki in a Senate match up. She led 58% to 32%.

The poll, which has a margin of sampling error of up to 4 percentage points, was taken between January 31 and February 3, the week after Mrs. Clinton gave a widely publicized speech on abortion in which she urged her fellow proponents of abortion rights to seek “common ground” with their opponents on the issue.

Mr. Pataki downplayed the new poll.

“I’ve seen polls go up and down, and you just don’t pay any attention to them,” he told reporters after a military awards ceremony outside Albany. “You lead with the policies and principles that you think will make this a better state.”

Mr. Spitzer kept a busy schedule yesterday, urging the governor and other state lawmakers to pass voting reform and lecturing students and teachers at St. Rose College in Albany on the principles that have guided his efforts to root out corporate fraud.

After addressing a crowded auditorium that included Albany’s mayor, Jerry Jennings, a Democrat who backed Mr. Pataki in 2002, Mr. Spitzer answered several questions about how he would conduct himself if elected governor.

Mr. Spitzer politely reminded his audience that he is not the governor, then suggested ways corporate fraud might be handled by the state’s chief executive. “I think you can do it by bringing into government people who share your ethical constructs and who believe in open government,” he said.

Mr. Spitzer’s interest in election reform took on special meaning at the Capitol yesterday, coming as it did on the same day as the Siena poll. He cast the reform issue as one that Republicans and Democrats should both embrace.

Mr. Spitzer is asking lawmakers to streamline New York’s voting system before a federal subsidy for such a project expires. He said New York stands to lose out on $219 million in federal funds for voting reform unless it outlines specific plans to update its voting system.

Two years ago, Congress passed a voting reform law aimed at ensuring straightforward elections. As part of the bill, states that update parts of their voting systems by 2006 will qualify for federal aid. Mr. Spitzer recommended yesterday replacing lever voting machines, computerizing voter registration lists, increasing the accessibility of machines, and improving oversight of poll operators. He also urged lawmakers to simplify the rules that govern vote counting.

Mr. Spitzer first addressed voting reform in 2000, saying then that changes would have to be made to avoid the irregularities that delayed the outcome of that year’s presidential election for weeks. Yesterday Mr. Spitzer cited the three-month battle over a state Senate seat in Westchester as fresh evidence the system needs reform.

“What was a concern four years ago, that New York could become Florida, has become a reality,” Mr. Spitzer said, referring to the race between a veteran Republican incumbent, Nicholas Spano, and a Democratic insurgent, Andrea Stewart-Cousins. “The 35th senatorial district has become Dade County.”

Following Mr. Spitzer’s first appeal for reform, Mr. Pataki established a commission to outline recommendations for change. A federal committee on election reform ultimately rejected the New York commission’s report as too vague to satisfy requirements for federal funds. Mr. Spitzer said a new report following his recommendations would have to be submitted by the end of this year to qualify for federal subsidies.

By seeking to win back the governor’s seat from the Republicans, Mr. Spitzer leaves a potential opening for Republicans at his current post. A strong Republican candidate has yet to emerge for that race, but momentum appears to be building for Jeanine Pirro, the Westchester district attorney. She has also been mentioned as a possible opponent for Mrs. Clinton.

Ms. Pirro told The New York Sun yesterday that she is focused on her current job. “I like my job,” she said. “I really do.”