For the last year, all eyes have been focused on the future of the Republican Party. Pundits love to talk about the collapse of the party, the fractures between social and fiscal conservatives, the number of party leaders who say they will not vote for the GOP nominee and what the party will do to rebuild the day after the election – in the wake of what the media now believes will be the defeat of Donald Trump.

But here's what no one is talking about – the one awkward subject that will stop a Washington dinner party cold and send guests into stunned silence – and that is, what if Hillary Clinton loses the election? Right now, it looks like the GOP will hold the House, and my U.S. News colleague Joseph Williams wrote recently that there are growing predictions Republicans will hold the Senate as well. If the Republicans sweep the House, the Senate and the White House, the Democratic Party will implode. Here's why:

First, I've long thought that the anti-establishment wave that hit the right this year is heading for the left. A Clinton loss only accelerates this wave. Just as it did on the right, it will sacrifice mainstream Democractic candidates and lead to chaos within the party's ranks. No one embodies the Democratic establishment more than the Clintons, who have built an empire in Washington and New York over the last three decades – and if she loses, the Clinton establishment will be blamed. The same issues that angered grassroots GOP voters – the decimated manufacturing base, sluggish economic growth, income inequality, endless and unsuccessful wars and the sense that leaders in gridlocked Washington "don't get it" – are feeding the disconnect between the Democratic base and its elected leaders. If Democrats think they escaped the anger that propelled Trump, they're wrong. It's heading their way next.

Second, if Clinton loses, Democrats will have to do some soul-searching on policy. It's already clear that Democrats are out of step with mainstream Americans on policy and a Clinton loss will jolt the party into confronting it. But it won't be pretty. Bernie Sanders dragged the Democratic Party to the far left during the primaries and sacrificed middle of the road and independent voters. The bad news for Democrats is they aren't coming back without major changes. If the party wants to build a governing majority next time, it needs to put a growing economy and job creation at the top of their list of priorities – not climate change and abortion rights. If it wants to continue to attract independent voters, it needs to offer serious plans for reforming Social Security and Medicare – as well as fixing the deep flaws in Obamacare – ahead of the tidal wave of retirees that has already begun rising. And if it wants to build a broader coalition that will attract voters on both coasts as well as in the Midwest and South, it needs to address the lack of economic opportunity in so many struggling cities and towns – instead of doubling down on failed nanny-state welfare policies and more gun control.

Third, a Clinton loss means millennial voters will abandon the party en masse. Current polls show many of them are unethusiastic about Clinton's candidacy, and turnout may not be what it was four years ago. I'd bet money that a nonestablishment, angry far-left candidate – younger and more charismatic than Bernie Sanders, less Larry David and more Jerry Seinfeld – will run in the Democratic primaries in 2020. And if the party wants to keep millennials motivated to stay involved in political change without starting a third party, it needs to do more than promise them "free" college tuition. For the people whom Clinton says are Sanders supporters "living in their parents' basements," the national debt will become more and more of an issue. Talking about $20 trillion in national debt isn't as fun as talking about "free" college education, but in the long run reducing the debt will be much more important to millennials – because it will directly affect economic growth, taxes, government spending and their ability to build a better life. So far, when it comes to fiscal responsibility, entitlement reform or reducing the debt, there's nothing but crickets on the left.

The final, and most important, reason the Democrats are in trouble if Clinton loses (and even if she wins, really) is the lack of future Democractic candidates. This year, the Republicans originally fielded 17 candidates for president in the primaries, compared to three Democrats and an aging Socialist on the left. The Democrats don't have nearly the deep bench that Republicans do across the country – 23 states have Republican governors and a Republican majority in both houses of the state legislature. The Democrats hold only seven of those trifectas. There are currently 34 Republican governors; Democrats number only 18. Republican state senators and representatives outnumber Democrats by nearly a thousand. The Democrats don't have nearly as many potential candidates in the pipeline as Republicans do – a huge problem for the long-term health of the party.