What a Trump loss could mean for Hillary Clinton's presidential mandate

Rogers: Donald Trump's problem is Donald Trump

Donald Trump appears headed for a major defeat on Nov. 8. The remaining questions are how badly he gets crushed, how many Republicans he takes down with him and what it will mean for Hillary Clinton's presidential mandate.

First, it's important to recognize that there are a few polls that show Trump still close or even in the lead — he trails in the Real Clear Politics average by more than 6 points. No candidate in modern presidential history has ever come back from that kind of deficit.

The most beloved poll these days among Trump true believers is the IBD/TIPP survey that now shows the race tied. This is often touted as the "most accurate" poll of that last several election cycles. But this poll showed a solid lead for Mitt Romney until very late in 2012 when it swung quite suddenly — and surprisingly — toward President Barack Obama and aligned itself more closely with the rest of the major national polls.

Do a quick Google search and you will find scores of articles in which conservatives clung to the IBD poll showing Romney ahead in 2012 while other surveys showed the race trending inexorably to the incumbent president.

Donald Trump at a campaign rally in Delaware, Ohio, on Oct. 20, 2016
Jonathan Ernst | Reuters

IBD also performed badly in 2008, suggesting Republican nominee John McCain had a large lead among younger voters. Obama won this group handily. As late as Nov. 2, 2008, IBD had Obama up just 2 points over McCain. He won by 7 points and carried 365 electoral votes, a landslide in the current highly partisan era.

So leave the outlier polls alone and focus on the average of all high-quality polls. And leave the "oversampling" of Democrats nonsense to the Bill Mitchell's of the world who spend a good part of their lives trying to "unskew" surveys showing Clinton with big leads.

There is a simple reason polls include more Democrats. Because more people identify as Democrat than Republican. High-quality surveys"oversample" certain groups to get a better picture of what the actual electorate looks like.

So barring a catastrophic collapse, Hillary Clinton is going to win. Even without including any of the "toss-up" states, Clinton right now is at 262 electoral votes. Eliminating toss-ups, Clinton is currently leading in enough states for 333 electoral votes, which would be a resounding victory, just short of Obama's 2008 numbers.

In order for Trump to win he would have to run the table in swing states, including Nevada, Florida and North Carolina. He trails in all three. Even winning all those would put Trump at 266. He would then need to flip at least one state leaning heavily toward Clinton, such as Pennsylvania, Virginia or Colorado.

It's more likely that Trump winds up losing states he has to win. He trails Clinton in Arizona and independent conservative Evan McMullin in Utah. He is only barely ahead in Texas and Alaska.

Clinton and Obama, meanwhile, are turning their attention to down-ballot races trying to deliver a mandate and possibly a friendly Congress to the Democratic nominee.

Taking over the House remains an unlikely scenario unless a very large wave develops to deliver Democrats the 30 seats they need. The Senate, however, remains a strong possibility. The party needs Clinton to win and at least four pickups to take the upper chamber. They appear certain to take seats in Illinois and Wisconsin. They could lose a seat in Nevada though the race for Harry Reid's seat remains deadlocked. Democrats lead in currently Republican-held seats in Missouri, New Hampshire and Indiana.

A big Clinton win at the national level will probably deliver very narrow Senate control to Democrats. The House will probably remain Republican. The question will then be how Republicans react to defeat and what approach they take to Clinton when she takes office in January.

A resounding rejection of Trumpism would likely lead to at least some willingness among Republicans to work with a Clinton White House in its early days with infrastructure spending and a simplification of the corporate tax code — including repatriation — high on the list of possibilities.

But Clinton's window for legislative movement will be extremely limited, even if she wins big. Republicans have a very friendly Senate map in 2018 and will be heavily favored to regain control should they lose it in November.

That means Republicans will want to try and draw sharp lines with Clinton early and avoid alienating an activist base that loathes the Democratic nominee. Even if Trump loses big, the hardcore base of the Republican Party, which turns out in midterms, will like punish Republicans seen as collaborators with the opposition.

So unless Clinton delivers a wipeout of historic proportions, Washington in 2017 will likely look much like Washington of the last few years, a gridlocked mess incapable of agreement on tax reform, infrastructure spending or immigration reform, leaving a softening economy to fend for itself.

—Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money [politico.com/morningmoney]. Follow him on Twitter @morningmoneyben.