Presidential candidates Sen. Bernie Sanders (I-VT) and Sen. Elizabeth Warren (D-MA) share many of the same ideological views, but they do not share the same base — a point of interest to onlookers of the Democrat primary.

The two senators have somewhat of an unofficial pact with one another. During a July 8 appearance on the California Nation podcast, Warren refused to explain the main differences between herself and Sanders, instead talking about their years of friendship.

“I’ve known Bernie and been friends with Bernie forever and ever and ever, long before I ever got into politics. I can’t talk about Bernie and what Bernie wants to do. He’ll get out there and make that case,” she said.

“We just don’t attack each other. It’s not about a pact. Bernie’s been my friend forever, and I’ve been his friend forever,” she added.

Sanders and Warren share many of the same views on key Democrat issues. Sanders built his 2020 campaign on lofty promises to eliminate private insurance and save the planet from “climate change,” frequently citing the “12 years” deadline made famous by freshman Rep. Alexandria Ocasio-Cortez (D-NY). Warren, though, is not far off in her own views.

“The problems are big and existential, she said, but not insurmountable — Americans faced Nazis in World War II and put a man on the moon during past crises,” she told a crowd in Michigan last month, according to the Lansing State Journal.

“We invested in science, we invested in innovation, and we invested in American workers making it here in America,” she continued. “Climate change?” 

“Yeah, it’s a tough challenge, but we’ve got a plan and we’re going to take it on, head on,” she added.

Warren has spoken glowingly about Sanders’ Medicare for All plan as well. NBC moderator Lester Holt asked her about that during the first Democrat debate.

“It would put essentially everybody on Medicare and then eliminate private plans that offer similar coverage,” Holt said. “Is that the plan or path that you would pursue as president?”

Her response was less than specific.

“I’m with Bernie on Medicare for All. And let me tell you why,” Warren said, claiming that Medicare for All would solve all industry problems. However, she failed to explain how it would do just that and slammed critics of her position.

“There are a lot of politicians who say, ‘Oh, it’s just not possible. We just can’t do it’ — have a lot of political reasons for this,” she said.

“What they’re really telling you is they just won’t fight for it. Well, health care is a basic human right, and I will fight for basic human rights,” she added.

Despite Warren’s and Sanders’ ideological similarities, they do not share the same base. While Sanders tends to appeal to low-income individuals with less educational background, Warren wins over individuals with postgraduate degrees.

As Politico reports:

In poll after poll, Sanders appeals to lower-income and less-educated people; Warren beats Sanders among those with postgraduate degrees. Sanders performs better with men, Warren with women. Younger people who vote less frequently are more often in Sanders’ camp; seniors who follow politics closely generally prefer Warren.

Sanders also has won over more African Americans than Warren: He earns a greater share of support from black voters than any candidate in the race except for Joe Biden, according to the latest Morning Consult surveys.

Identity politics may also be at play, with some Democrat voters looking for a change and leaning toward Warren due to her status as a female.

While Sanders has remained in the top tier of Democrat candidates since his official announcement, Warren eventually made her way up from the second tier, finding herself in a fierce battle with Sanders and Sen. Kamala Harris (D-CA) for second and third place.

It goes to show, though, that there is more to play than ideology alone. There is no guarantee that Warren’s voters will eventually flock to Sanders or vice versa as the field narrows:

For progressive activists, who are gathering this week in Philadelphia at the annual Netroots Nation conference, it’s both promising and a source of concern that the two leading left-wingers in the primary attract such distinct fans. It demonstrates that a progressive economic message can excite different parts of the electorate, but it also means that Sanders and Warren likely need to expand their bases in order to win the Democratic nomination.

Advisers for Sanders say he needs to work on gaining the support of older Americans, as the young voters — who have traditionally gravitated toward him — find themselves slowly looking to younger, “woke” candidates:

“Two places where Bernie has always struggled with is older voters and women to some degree,” said Mark Longabaugh, a top strategist to Sanders in 2016. “Warren is identifiably a Democrat and runs as a Democrat, so I think many more establishment Democrats in the party are more drawn to her — whereas Bernie very intentionally ran for reelection as an independent and identifies as an independent, and appeals to those who look inside the Democratic Party and think it’s not their thing.”

The current Real Clear Politics average shows Sanders and Warren tied for second place, each with 15.2 percent. Harris follows closely behind with 15 percent even.