The ultimate problem that Sen. Bernie Sanders, I-Vt., faces right now, after announcing his intention to again seek the Democratic Party's nomination for president, is that Democratic voters aren’t fully aware of his record — yet.

That may seem counterintuitive after the rough 2016 primary and his supporters' blanketing of social media. But, in truth, the 2016 Clinton campaign never named him in a single negative television or digital ad. And the media never truly educated the primary voting public with the intensity reserved for candidates seen as viable: His underdog status protected him then, but he won’t have that this time around.

There were, of course, numerous news stories that covered Sanders’ positions throughout the campaign, in between the obsessive coverage detailing the gritty ins and outs of the latest in the Clinton email scandal. A study from Harvard's Shorenstein Center on Media, Politics and Public Policy suggests as much: Only seven percent of his coverage was about his policies, but 83 percent of that was positive, whereas 28 percent of Clinton's coverage was policy-based and 84 percent of that was negative.

"Journalists," the study said "made more references to her past history than they did to those of other candidates and focused on the negative."

They did not do the same with Sanders’ gun safety record or his reluctance, until recently, to embrace marriage equality.

If Sanders’ team of consultants gave him some honest advice about what the 2020 election will be like, they’ll have told him it will be much harder than his experience in 2016 — both because he won't be facing Clinton, and because the differences between his policies and those of others in the field won't be as distinct.

So, while in 2016 he cultivated a reputation around popular left-wing positions like Medicare-for-All and free college, the broader embrace of those issues in the Democratic party means that his opponents in a second presidential campaign will inevitably address his lesser-known and decidedly less progressive record on the issues that cut directly against his liberal brand.

For example, many Democratic voters may now be surprised to learn that Sanders opposed a staggering number of gun safety measures throughout his career. He voted five times against the Brady Bill, a common-sense measure mandating a waiting period and background check before purchasing firearms. Rather than apologize, his 2016 campaign doubled down: His top aide, Jeff Weaver, characterized the Brady Bill, in Politifact’s words, a "federal overreach."

When that didn’t silence the criticism, the Sanders team pointed to the senator’s support for a substitute amendment implementing “instant” background checks instead. What they didn’t say was that the National Rifle Association actually backed that amendment as a sneaky way to neuter the larger bill; technology didn’t exist in the early 1990s to perform the “instant" checks the amendment demanded.

But Sanders’ gun votes don’t end there: He voted to allow firearms on Amtrak trains; he voted to create what is now called “Charleston loophole” that allowed Dylann Roof to obtain the weapon used to murder nine African-Americans in a Charleston church in June 2015. He even voted repeatedly against holding gun manufacturers liable for the destruction caused by their products, which was strange because he supported similar consumer protection measures for other industries, like food manufacturers.

Still, he felt so strongly about protecting the gun industry from lawsuits that he actually defended his votes on the campaign trail before being forced to flip flop.

Democratic voters who listened to his relentless attacks on Clinton (who wasn’t even in Congress at the time) over the 1994 Crime Bill — which was partially responsible for the mass incarceration crisis facing our country — might also be shocked to learn that Sanders voted for it. The excuses for his vote were pathetic: His supporters pointed to the fact that he gave a strongly-worded speech condemning aspects of the bill before casting a vote in favor of it.

This team also claimed that he gave his support because it included other provisions that he liked, an explanation that is undermined every time he cites smaller objections as a reason to vote against other large pieces of legislation — like when he voted to tank Sen. Ted Kennedy’s comprehensive immigration reform bill in 2007 by citing the inclusion of a guest worker program.

During the 2016 campaign, he claimed to oppose the included guest worker program because it was akin to “slavery.” But in a video of Sanders, later revealed, trashing the legislation on anti-immigrant Lou Dobbs’ TV show, he never likened the guest worker program to slavery. Nor did he make that argument when he voted for a similar program in 2013. Instead he made a nativist argument about how the legislation would reduce wages for Americans by bringing in low-wage temporary workers.

But there’s more that Democratic primary voters won’t like.

He will have to explain his wishy-washy past on same sex marriage: Until 2009, he said it was a matter for the states to decide, and even told a reporter in 2006 that Vermont should not pursue it at all.

And he’ll need a better explanation, post-#MeToo, for his disturbing 70s-era essay about rape fantasies and what it means about his attitude towards women. (That is especially true in light of the allegations of sexual harassment at his campaign offices, the resulting $30,000 settlement and his initial cavalier response that he was too “busy” to intervene in the culture of misconduct at his operation.)

Nor will he be able tell his critics to lay off their critiques for the sake of unity, especially given that his supporters are already in full-blown attack mode tearing down other candidates.

It's clear that the Democratic Party should be grateful that Sanders helped move the conversation to the left on issues like health care and education during the 2016 primary and in the years since. However, it is difficult to see how he surmounts his more conservative record on other key issues when there are so many progressive candidates to choose from who are espousing similar policies — and when Hillary Clinton is not on the ballot to kick around.