It feels good, doesn’t it, Democrats? Donald Trump is imploding. Republicans are in an open, bloody revolt. And the polls look so good for Hillary Clinton, you’re starting to believe that this might really happen.

It’s probably tempting right now to start to wonder what you’ll push through first when you’re in charge — climate change or immigration reform? Card check or the public option? With the White House and maybe even the House and Senate in Democratic control, you just might have the numbers to do it all.

But before you make plans for a progressive Utopia, take a minute to think about why Clinton is leading right now and why it matters. It’s clear that she isn’t winning because a majority of voters love her, trust her and are embracing her ideas. Most Americans still say they don’t find Clinton to be honest or trustworthy. Against any other Republican, she’d likely be losing. But because she has the luck of running against a disaster like Trump, she’s poised to win it all.

But a victory for Clinton, even a landslide, won’t be a mandate for her vision or for a progressive agenda. It will be because a majority of independents and some number of Republicans had nowhere else to go. They’re like flood victims who move in with the neighbors they don’t like very much, but who at least offered them a place to stay while they rebuild their own house.

[Trump Says He’s Taking the ‘Shackles’ Off]

Democrats have a historic opportunity to keep those Republicans with them by making room for them to stay after November and the years to come. In the same way that Reagan Democrats switched their allegiance to Ronald Reagan’s Republicans in 1980, Democrats could mark this as the year that “Clinton Republicans” leave their party and stay gone.

Or Democrats can grab their win, jam through as much of their wish list as possible and add 2016 to the pile of years when a party won a wave election, overplayed its hand, and then lost the next cycle in a rebuke from fed-up voters.

When President George W. Bush won his second term in 2004, he famously declared that he had “earned political capital in [this] campaign and now I intend to spend it.” By January 2007, Republicans had lost six seats in the Senate, 30 in the House, their majorities in both chambers and the governors’ mansions in six states. Between his own re-election and the 2006 midterm elections, Bush bungled his handling of the Iraq War and Hurricane Katrina, and tried to pass Social Security privatization and an overhaul of immigration laws. In two short years, he had spent all of his capital and had nothing to show for it.  

After President Barack Obama won the White House in 2008 and Democrats held on to the House and Senate, they rushed to push through two longtime progressive goals — health care reform and climate change legislation. “Cap and trade” got through the House, but not the Senate, while the Affordable Care Act had to pass under a budget reconciliation rule without attracting even one Republican senator to support it.

[Forget About Great People, Where Are the Good Ones?]

The 2010 elections and the tea party movement that preceded it were the report card on Democrats’ approach. Local protests against the health care law in 2009 grew so intense that CNN started carrying congressional town hall meetings live during the August recess anticipating the protests and anger that followed. House and Senate Democrats got obliterated the next November.

Pause the tape and hit “replay” in 2011, when an emboldened Republican majority forced a showdown over the debt ceiling, pointing to the 2010 elections as proof that this was the direction voters wanted. It wasn’t. President Obama won re-election in 2012, thanks in large part to voters’ frustration over a Congress that couldn’t perform the basics of governing.

And that brings us to 2016. If Clinton does win, she will have to build the trust of American voters, who have given the White House to her instead of a man who praises Vladimir Putin, threatens to jail political opponents, and was just caught on tape bragging that he can grab womens’ genitals. It’s not exactly the stuff of mandates.

Clinton’s slogan is “Stronger Together,” which she says applies to all Americans, no matter their race, gender, ethnicity, and I assume, political party. With the agenda they choose to pursue, she and the Democrats have a once-in-a-generation opportunity to prove that’s really true.

Roll Call columnist Patricia Murphy covers national politics for The Daily Beast. Previously, she was the Capitol Hill bureau chief for Politics Daily and founder and editor of Citizen Jane Politics. Follow her on Twitter @1PatriciaMurphy.