In eight years as New York’s U.S. senator, Hillary Clinton was sole sponsor of just three laws: a post office designated for a military hero, a historic site honoring a labor leader and an upstate road named for Tim Russert, the deceased host of NBC’s Meet the Press.

Yet her behind-the-scenes efforts — co-sponsoring bills and using committee assignments, corporate connections and celebrity — give her an edge against Vermont Senator Bernie Sanders in New York’s April 19 presidential primary. In a state where convention delegates are apportioned to the candidate who wins each congressional district, she has endorsements from all 18 of the state’s Democratic members of the House of Representatives.

Clinton left the Senate as one of the state’s most popular politicians after helping push the Bush administration to fund the rebuilding of lower Manhattan after the Sept. 11, 2001, terrorist attacks. She’s also credited with supporting farmers and manufacturers in depressed upstate areas. Voters gave her a 62 percent approval rating just before she left to become Secretary of State for President Barack Obama, up from 30 percent when she took office in 2001, according to the Marist College poll.

“What impressed me was how much she did her homework, how hard she worked and how little she cared about the spotlight,” said Nabil Nasr, an entrepreneur and expert on manufacturing and technology at Rochester Institute of Technology.

Nasr can’t remember whether he’d even voted for Clinton when he first met her, weeks after she took office, at a gathering of executives she invited to discuss renewable energy and industrial recycling. “What began that day is still paying dividends today,” said Nasr, who last week attended a campaign rally for her.

As Rep. Charles Rangel tells it, the idea to turn the Illinois native and Arkansas resident into a New York senator began in 1997, just a year after her husband, Bill Clinton, won a second presidential term. In September 1999, less than a year after Bill Clinton was impeached, they became New Yorkers, purchasing a $1.7 million 11-room Dutch Colonial home in Chappaqua, a Westchester County hamlet. In November, she announced her Senate candidacy.

“She went around the state on a ‘listening tour’ to dispel the depiction of her as a carpetbagger.” said Rangel, a Democrat who’s represented Harlem since 1971.

Clinton cruised to victory in 2000, beating Republican Rick Lazio, 55 percent to 43 percent after a far-tougher competitor, former New York City Mayor Rudy Giuliani, decided not to run. She won a second term in 2006 with 67 percent to 31 percent for former Yonkers Mayor John Spencer.

In Washington, Clinton accepted a small office on Capitol Hill, fetching coffee for colleagues and reaching out to befriend the same Republicans who had pushed to impeach her husband, said journalist Carl Bernstein, author of “A Woman in Charge,” a 640-page biography.

“She was deferential, determined to show them how serious she was,” Bernstein said in an interview. “Was she good at delivering the bacon to her constituents? Absolutely. Did she deliver important legislation on the major issues of the day? Absolutely not.”

Clinton championed causes for which she could build bipartisan consensus, Bernstein said.

She teamed with Republican senators: Lindsey Graham of South Carolina, to extend military health benefits to 356,000 National Guard and Reserve members, and Mike DeWine of Ohio to force drug companies to conduct pediatric safety tests.

Clinton sponsored bipartisan legislation with New Jersey Rep. Mike Ferguson to provide respite care to families caring for disabled adults and children. She took up an issue advocated by former Republican Sen. Bob Dole of Kansas and, with Democrat Chris Dodd of Connecticut sponsored an extension of the Family and Medical Leave Act to give military families six months to care for the wounded.

“She was a very hard worker, and you could count on her to have done her homework,” said former Republican senator John Warner, chairman of the Armed Services Committee, which she joined in 2003. “She was very conscious of family issues as they related to the men and women of the armed services.”

Her ambition to be president probably motivated what she now calls a mistake — her approval of the October 2002 Iraq war resolution that gave former President George W. Bush permission to invade the country, Bernstein said.

In her 2014 memoir, “Hard Choices,” Clinton said she “absolutely” regretted the vote. It was fundamental to Obama’s 2008 victory against her for the Democratic presidential nomination. Sanders has used it against her this year.

In New York, however, Clinton leads Sanders 55 percent to 41 percent among registered Democrats, according to an April 11 Marist College poll. Her tenure as senator gives her personal connections and voter recognition, said Stuart Rothenberg, founding editor of the nonpartisan Rothenberg and Gonzales Political Report in Washington.

“Voters in the state feel like they know her, they voted for her,” Rothenberg said.

Sanders has tried to offset this by stressing his Brooklyn upbringing, although his appeal probably comes from his populist focus on income inequality, Rothenberg said.

“He’ll do well in Ithaca and other places with universities,” Rothenberg said. “But if she gets another big African-American showing and holds onto Democratic women and Democratic regulars, she’ll do fine.”

Days after Sept. 11, Clinton and Charles Schumer, New York’s senior senator, along with House members, won a promise from Bush to provide more than $20 billion to redevelop the World Trade Center and Lower Manhattan’s financial district. She chaired the first Senate hearing probing the health of survivors, which buttressed a drive to create a fund for victims and first responders, many of whom developed chronic illnesses from toxic smoke and debris.

In June 2002, the Senate passed a measure she co-sponsored that requires the government to compensate insurers for much of the losses incurred from terrorist attacks. And in 2004, Clinton won amendments that provided $50 million for nonprofits and community groups at risk of terrorist threats and $570 million to protect New York’s trains and tunnels.

Her news releases touted $400,000 for St. Joseph’s College in Brooklyn and $900,000 for the endangered Oak Beach Park on the Long Island’s south shore in 2004. In 2005, she and Schumer announced they had secured $1.4 billion for Amtrak.

Between 2008 and 2009 Clinton secured 292 appropriations “earmarked” to benefit New Yorkers totaling $351 million, ranking 13th among her colleagues, according to Citizens Against Government Waste in Washington, a group advocating small government.

Former Republican representative James T. Walsh, who represented the Syracuse region from 1989 to 2009, says Clinton won friends among his constituents promoting upstate farm produce in New York City and on Capitol Hill with an annual New York Farm Day.

“She was big on apples, big on wine,” said Walsh, now a Washington lobbyist with K&L Gates. “She combined upstate agriculture and downstate palates.”

(c) 2016, Bloomberg · Henry Goldman, Laura Litvan