There is only one thing certain about the outcome of the 2016 election – it will produce more gridlock. On January 20, 2017 Hillary Clinton or Donald Trump will assume the office and the nation will have either a divided government or one-party rule – neither of which are likely to create a bipartisan surge. One outcome will look quite familiar: a divided government led by a Democrat in the White House. Another possibility: One-party rule by a Republican Party in the midst of serious fractures under the leadership of a very nominal Republican. The least likely scenario also involves one-party rule, but instead by the Democrats.

In the first scenario, Clinton would likely be able to fill the vacancy on the Supreme Court. But it's also possible that Republican Senate leaders, arguing that Merrick Garland will be less liberal than a Clinton pick, will allow a vote on President Barack Obama's nominee to the seat in a lame duck session. It's also possible that Garland could get a vote even earlier if Senate Republicans are feeling desperate after Labor Day and believe a vote on Garland would improve their odds to hold the Senate. Still, Republicans in the minority could also filibuster a Clinton Supreme Court selection for an indefinite amount of time.

A President Clinton might be more adept at cultivating personal relationships with congressional leaders than President Obama was, which some observers believe hurt Obama's presidency. But the larger problem – that of two diametrically-opposed partisan camps each holding power in Washington – would remain, and it's doubtful that a GOP House majority would go along with any big-ticket Clinton proposals. For example, any gun control initiative – a Clinton focus during her primary with Sanders because it was one of the few issues where she could get to Sanders' left – would likely be dead on arrival in the GOP House.

A major unanswered question in this scenario is how rank-and-file Republicans would react to the hypothetical Trump loss and the loss of the Senate. We know from public opinion polling, and from the outcome of the Republican presidential primaries, where candidates affiliated with the so-called "party establishment" did quite poorly, that Republicans dislike their leaders and prefer outsider candidates to insiders. Would that change after a third straight presidential defeat? Would the party base become less rebellious and acknowledge a need for moderation? The signals Republicans get from their own supporters in the aftermath of 2016 will guide their willingness to compromise with Democrats.

One thing seems fairly clear, though, and it argues against compromise: Hillary Clinton is already unpopular, and Republicans will have political incentives to make her first two years miserable and unsuccessful so they can run against her in the 2018 midterm. If Republicans lose the Senate in 2016, they should have an excellent chance to retake it in 2018: Democrats are overextended on the 2018 map, where they already hold 25 of the 33 seats up for election. That includes defending five seats in states that Republicans have carried in at least the last four presidential elections and that Trump is currently favored to carry as well: Indiana, Missouri, Montana, North Dakota and West Virginia. Additionally, Democrats will be defending Senate seats in competitive swing states like Florida, Ohio, Virginia, and Wisconsin, among others. The president's party has lost ground in the Senate in 19 of the 26 midterms held since 1914, the first election featuring direct election of senators across the country.

If Clinton wins the White House without carrying the Senate, the dynamic would be much the same, although Republicans would probably feel even more emboldened to battle Clinton because an election outcome like that would be more a repudiation of Trump than a repudiation of the GOP. The party would feel the same impetus to stymie Clinton to set up the midterm and a 2020 presidential election that Republicans would likely feel confident of winning in large part due to popular fatigue amongst voters after more than a decade of Democratic presidents.

The second possibility, a unified Republican government under President Trump, is harder to handicap. However, we must assume that a presidential candidate running aggressively on particular proposals will try to enact them. So, if Trump is elected, we should not be surprised if he tries to follow through on what he's campaigned on, including trying to build a wall on the nation's southern border with Mexico while attempting to get Mexico to pay for it by threatening to cut off the remittances that immigrants send to their home country from the United States. Whatever one thinks of the proposal, there's little reason to think Trump won't try to implement it, through Congress or perhaps by executive order. The Senate will also have to vote to confirm Trump's Cabinet appointments, and it's not a given that every nominee will pass smoothly through the Senate. Congressional Republican leaders would likely try to mold Trump in their own image, but not only is Trump a natural renegade, Congress would also be fighting against a White House that, in the long reach of American political history, has been growing in strength relative to Congress, not weakening. The chance of a conflict between the executive and legislative branches, even in a one-party Washington, seems real, and the possibility exists for a constitutional crisis. Military leaders, for example, might not follow certain orders from a commander-in-chief Trump, such as a directive to execute a suspected terrorist's family members or engage in torture.

The same midterm problems that could threaten the Democrats under a President Clinton, including a recession and a potentially unpopular president, could hurt the Republicans under a President Trump in 2018. While the Republicans would still have an advantageous Senate map in 2018, the GOP's House majority could very well be endangered. The midterm trend against the president's party in the House is even clearer than that in the Senate: There have been 39 midterms since the Civil War, and the president's party has lost ground in the House in 36 of them.

Finally, a third possibility for 2017 is that Trump is such an electoral disaster that Clinton not only wins the White House but she is also swept in with a Democratic Senate and House. The chances of this are small, but certainly not unprecedented.

The next Democratic House majority, whenever it comes, probably will be the most uniformly liberal of modern times. The old conservative Democratic blue dog is essentially extinct, and the Democrats' most plausible path to winning back a House majority involves winning battleground suburban seats as opposed to the conservative southern and Appalachian districts that Democrats used to hold. Still, even if Democrats won the House, they likely would be several seats short of a filibuster-proof majority in the Senate. This would give Senate Republicans the option of stopping big ticket Democratic policy proposals, such as an expansion of the Affordable Care Act or even a major legislative push to address climate change.

This could lead the Democrats to simply do away with the filibuster, reducing the effective threshold for most action in the Senate from 60 votes to 51 votes.

Yes, Republicans would vehemently oppose such a move, although there's the possibility that they could eventually do the same thing (perhaps even during a period of unified Republican government under a President Trump). As Henry Olsen of the Ethics and Public Policy Center argues, the filibuster – and its frequent use – forces coalition government on two parties that have no interest in working in a coalition. It raises the bar for action to 60 votes when it is very hard for either party to win 60 votes in the Senate, and when there are relatively few senators who cross over to vote with the other party on many issues. The filibuster has already been eroded, including by the Democrats in 2013 when they eliminated it for most nominations in order to confirm a number of judges and other officials that Republicans blocked. Doesn't it seem possible that its total elimination is just a matter of time, particularly as two increasingly divergent parties find themselves increasingly frustrated by its use?

Perhaps that seems implausible. But we're in an era where the first African-American president is set to be succeeded either by a reality television star or the first woman president. In American politics, things that at one time seemed quite implausible are now happening with some regularity.