After a messy Iowa caucus that had Buttigieg questionably edging out Sanders in pledged delegates, Bernie can now declare himself the frontrunner after his impressive victory in New Hampshire.

Although he won by only a few thousand votes, it's how Bernie won that matters.  Biden had another poor showing in New Hampshire that will have him playing catch-up heading into Super Tuesday.  In the same primary, Warren, Bernie's progressive counterpart who not too long ago was poised to steal the reins from him, received only 9 percent of the vote and is polling poorly in both Nevada and South Carolina.

With such a decisive lead, Bernie has a clear path to be nominated, and simulation models show him to have a one-in-three chance of being the candidate who will face Trump in November.

Four years ago, Trump also established himself as the clear frontrunner heading into South Carolina and Nevada and was never able to fully unify the party until he became president.  Trump was always able to pose as the outsider fighting the powers that be.  There was not only a practical, but also an emotional side to rooting for the defeat of the political machine that worked so hard to subvert Trump even after he clinched the nomination.

In this sense, Hillary was the best opponent that Trump could ask for — a puppet of the entity against which Trump was fighting.  Four years later, Sanders is enjoying the same success and, despite his being the frontrunner, still has an underdog vibe while also preaching a populist message.  Therefore, it won't be surprising if a "Never Bernie" sect of the party emerges if he becomes the nominee.

The question is, how would Trump campaign against an outsider candidate now that Trump is on the inside as president?  Primarily, a Trump vs. Sanders contest would be about who can appeal more to the common working-class man.  This will be especially true for competing in the Rust Belt, which will have to become Trump's firewall if he is to hold off a candidate whose rhetoric is tailored toward Rust Belt voters.

Trump can and should point to his successes in renegotiating NAFTA, bringing back manufacturing jobs, and supporting the coal and natural gas industry as reasons to support him over Bernie, who is still just talk at this point.  It also doesn't help Bernie's populist cause that he has to toe the line when it comes to supporting liberal policies such as undermining the coal and natural gas industry, which would further hollow out Rust Belt communities.

Trump can also win on taxes, despite the usual liberal mantra that Republican tax cuts disproportionately benefit the wealthy.  The simple facts are that most Americans want to be taxed less, not more, and that lowering taxes spurs economic growth, which is partly why Trump currently presides over a robust economy.  As such, Bernie's admission that he would raise taxes on the middle class may not help him make his case to blue-collar workers, who are mostly in the middle class.  Trump would be smart to emphasize this point in his upcoming campaign.

Just as Trump began taking shots at Hillary when it was evident that she would win the nomination, Trump will soon have to consider doing the same with Sanders if he continues to win states and rack up delegates.  Even though Trump won't admit to preferring to face one crazy Democrat candidate over another, Sanders would pose the biggest challenge to Trump on the debate stage and on the map as well.  Leaders within the party and Democrat voters may be starting to realize this, which may explain his recent surge in the polls, especially in demographically diverse states.

Even so, it would take a miraculous turn of events for Trump not to be re-elected this November.  Democrats realize this, which is why they went all-in on a Mueller investigation and an impeachment trial that lacked any validating evidence from the start, undermining the candidates' efforts to oust Trump democratically by trying to oust him legally.