Democrats are wandering around in the wilderness once again, shut out of power in Washington after losing a close, hard-fought presidential battle. The last time this happened, after the 2004 elections, the newly reelected president, George W. Bush, over-read his mandate and launched an ill-fated effort to partially privatize Social Security, providing a rallying point for Democrats to begin turning things around.

In an interview with me, House Dem leader Nancy Pelosi argued that history might repeat itself, if House Speaker Paul Ryan — with Donald Trump’s blessing — makes good on his hints to press forward with his plans to privatize Medicare. Pelosi vowed that Democrats would remain united in the battle to stop Ryan’s plan, a goal she described as crucial to defeating it, just as unity enabled Dems to block Bush’s Social Security plan.

“At that time, we committed to each other that we would be unified and disciplined,” Pelosi said. “Bush had just been elected. He gave us an opportunity by saying he would partially privatize Social Security. Everybody stuck together. The opportunity that we have now is the equivalent of the opportunity we had in ’05.”

In that 2005 fight, Pelosi recalled, Democrats actively avoided developing an alternative plan to Bush’s. Instead, Democrats said their plan was to defend Social Security, a very popular government program.  At the time, some Democratic strategists warned against uncompromising opposition. But the gamble paid off. Observers noted that Bush’s plan sank in popularity as Dems remained unified behind a refusal to budge in defense of Social Security, a move that was widely credited with helping to put Dems on track to winning back Congress in the 2006 elections.

Pelosi argued that if Republicans did try to privatize Medicare, it would afford a chance to underscore “the difference between Democrats and Republicans” at a time when Democrats are trying to regain their footing after this year’s loss. “This is such a stark difference that people know we have to be unified,” Pelosi said.

All indications are that Ryan hopes to push forward with some form of his long-entertained plan to turn Medicare into a premium support system, which is designed to put Medicare on sounder financial footing by giving Medicare beneficiaries vouchers to buy insurance — either private or traditional Medicare. In a recent interview, Ryan suggested this is on the table. Ryan has also taken to claiming that “because of Obamacare, Medicare is going broke,” which is totally false, and seems designed to lay the groundwork to transform Medicare as part of the drive to repeal Obamacare.

Opponents of Ryan’s plan argue that, since these voucher payments would not rise as fast as health care costs, it would merely save money by forcing seniors to pay more out of their own pockets over time. They also point out that Obamacare has already improved Medicare’s fiscal outlook.

It’s unclear whether Trump will go along with Ryan’s plan — doing so would require Trump to reverse himself on his campaign promise not to touch entitlements. But Trump does not appear to care as deeply about this debate as Ryan long has, and it’s reasonable to surmise he might be willing to go along with Ryan’s plan in exchange for other things he wants.

Regardless, Pelosi adamantly stated that Democrats would not give any ground on the core ideological dispute here, which is over whether to maintain a government coverage guarantee. “We are not going to a casino — this is a guarantee,” Pelosi said. “This is a value system for us, and we will fight for it. Is it a guarantee, or not?”

The liberal-leaning Center on Budget and Policy Priorities has argued that claims of Medicare’s impending fiscal doom are overstated, and that the fiscal problems the program does face can be addressed without harming vulnerable beneficiaries or compromising its core health care guarantee.

Asked if she worried that some House Democrats in tough districts or in states won by Trump might feel tempted to embrace the Ryan plan, Pelosi rejected the idea, insisting that the Democratic position is potent even in very red territory. Asked if some Democrats might feel drawn to supporting tweaks to Medicare, such as raising the eligibility age, Pelosi replied: “I don’t think that’s a place where members will go,” though she did say that Democrats must remain open to a discussion of ways of increasing its solvency.

It’s always possible that even if Democrats do maintain unity, Republicans could also remain unified and pass the Ryan plan without them. But in 2005, the Dems’ hard line helped fracture Republican unity behind Bush’s plan, leading to its defeat, and Pelosi hopes the same thing will happen again.

“Medicare, Medicare, Medicare — this is the plan,” Pelosi said. “It’s ideological with the Speaker to take away the guarantee of Medicare. But that is a fundamental pillar of health and economic security. And we will not go down that path.”