The recent death of Justice Antonin Scalia shows how much impact a single person can have in our system of government. In an instant, a conservative majority on the Supreme Court evaporated, turning sure-thing decisions against unions, abortion access, immigration, gerrymandering, environmental protection and affirmative action into live issues up for debate.

A change just as momentous will take place next January, when President Obama leaves office after eight years.

Programs that are the bulwark of the American safety net, like Social Security, Medicare and the Affordable Care Act, are at risk, and so are the nation’s relations with its allies and adversaries abroad. Obama’s replacement may not only pick Scalia’s successor on the Supreme Court, but could also name replacements for two or three other justices who are well beyond retirement age, setting the court’s course for a generation.

With so much at stake in November, Maine Democrats have one clear choice for their party’s presidential nomination: It’s Hillary Clinton.

Clinton is running against Vermont Sen. Bernie Sanders, who has energized progressives by arguing that the nation needs fundamental change to fix fundamental problems – most importantly, the concentration of wealth in an increasingly small number of hands.

We think that Sanders has identified the right issues, and we would be hard pressed to find a major goal of his candidacy with which we disagree. But we are less confident in his ability to assemble the overwhelming progressive majority that he acknowledges would be necessary to achieve the kinds of changes that he advocates.

Clinton has the experience and the temperament needed to navigate the complicated politics of a sharply divided nation. We think she would be best suited to fight to preserve social programs, which are always under attack, as well as to seize opportunities to make small but significant gains that improve people’s lives.

The checks and balances in the American system of government do not make revolutionary change easy. The system favors persistence, and Clinton has been nothing if not persistent.

Her entrance onto the national policy stage as first lady was a failure – a national health insurance program that was shot down in Congress. But she followed that by backing the State Children’s Health Insurance Program, which extended coverage to children with no access to health care. She worked with the bill’s sponsors, Sens. Ted Kennedy, D-Mass., and Orrin Hatch, R-Utah, and lobbied her husband’s administration and Congress to make sure the program was part of the budget. Then she worked with the states to help them set up their programs and enroll millions of children.

Kennedy later said that the program would not have existed if not for Clinton’s support.

That kind of effort continued during her eight years in the U.S. Senate, where, as Sen. Robert Byrd, D-W.Va., once put it, she developed a reputation as a “workhorse, not a showhorse” who had good relationships with colleagues on both sides of the aisle.

Her four years as secretary of state are characterized by her speaking up for women’s rights in parts of the world where no one else in power was doing it.

Clinton’s record is far from perfect, but perfection is not the right standard to judge such a long and varied career.

She is the best qualified candidate in this race, and she is the best qualified candidate to run for president in a very long time.

With all that’s at stake in this election, Maine Democrats should support Hillary Clinton at their caucus Sunday.