Bernie Sanders has trailed in the polls for weeks and appeared to be falling out of reach of catching Hillary Clinton, but now is picking up ground and could have a secret weapon in taking out the presumed nominee — Donald Trump supporters.

Sanders is approaching the start of the primary season solidly behind Clinton, with an average of double-digit deficits in polls. But he has strengths in some important areas, including the key early states.

And Sanders believes he could make up even more ground by tapping into the frustration felt by Donald Trump’s supporters. Though Sanders and Trump exist at opposite end of the political spectrum, there is a common thread running through their supporters — many of whom are fed up with the normal political process and believe that and outside influences are needed to make any real change.

In an appearance on CBS’s Face the Nation on Sunday, Bernie Sanders made a strong pitch for Donald Trump’s supporters to instead vote for him. He noted that many of Trump’s supporters are working-class people and are angry, working long hours and earning far less than their wealthier counterparts.

Bernie Sanders said these are all legitimate concerns, though he said Trump is handing them the wrong way. Instead of taking their fears seriously, Trump is playing on their fears and turning them against Mexican immigrants and Muslims, Sanders said.

It is difficult to say if Sanders’s pitch would be received well. While the theme of haves vs. have-nots is commons among his and Trump’s supporters, the stances regarding Muslims have been very well received. Polls found that more than 60 percent of Republican voters approved of Trump’s proposal to ban non-U.S. Muslims from entering the country, so winning over these supporters may be more difficult.

Didn’t get a chance to catch me on TV this morning? Get the recap here: https://t.co/U8mFIq14JY — Bernie Sanders (@BernieSanders) December 27, 2015

Bernie Sanders could also be gaining ground beyond the polls. Salon noted that he is building momentum in other areas, including some strong performances in Iowa polling. The all-important state would represent a major win for Sanders, and the report said it is within reach. For one, Sanders is doing better against Clinton than Obama did in 2007, when the Illinois Senator pulled off a surprise win over Clinton that helped propel him to the nomination.

The latest poll from CBS puts Sanders just 5 points behind Clinton, well better than the 14.9 percent average lead she had maintained through December.

Sanders is also holding onto his lead in New Hampshire, another early state that is something close to home ground for the Vermont Senator.

Sanders would need strong performances in both those states, Salon noted.

“Top Sanders aides have called both New Hampshire and Iowa must-win states, because the states that follow, Nevada and South Carolina, are seen as Clinton strongholds. Both Bill and Hillary Clinton have spent enormous energy in recent years to build bridges with leaders in Latino and African-American communities. That creates a big hurdle for Sanders, whose response has been to reach out to younger activists like his recent sit-down with Atlanta-based artist and actor Killer Mike.”

Bernie Sanders is also building on his strength in fundraising, following Obama’s model of gathering many smaller donations from a wider net. He has already broken Obama’s record of 2.2 million total donations.

But for Bernie Sanders to have a real chance of beating Hillary Clinton, he will need to make a serious move in the polls in the coming weeks, as losses in either of the first two states could be the effective end of his chances of winning the nomination.

[Picture by Mark Wilson/Getty Images]