Democratic U.S. Senate nominee Beto O’Rourke had a surprise this week that upstaged Republican incumbent Ted Cruz’s formal reelection kickoff—O’Rourke’s campaign has announced that he raised $6.7 million in the first quarter of this year. That’s more money than any Democratic U.S. Senate candidate has had in Texas since Ron Kirk’s 2002 campaign.

But it also drew attention to something else about O’Rourke’s fundraising, most of which has been done over the internet. Through his February 14 campaign finance report, O’Rourke declared that he has spent $2.6 million for online fundraising services to Revolution Messaging, a progressive operation run by former members of Bernie Sanders’s 2016 campaign for president. O’Rourke told me that he paid no attention to the company’s past clients when he hired them, only what the company and its people could do for his campaign.

O’Rourke’s hiring of Revolution Messaging could be viewed as controversial, even a little gutsy, given the bitter feelings that remain between Democratic factions in Texas who supported Sanders versus those who supported Hillary Clinton in 2016.

“They just have been a really effective technical team for us in making sure that we get digital media, that we get our email newsletter, which we write in-house. I mean, any email signed by me I write personally, any email signed by my team is my permanent staff, and they (Revolution Messaging) make sure that the mail goes out and they get out,” O’Rourke said Tuesday. “We’ve been running now for more than a year. We’re just really focused on Texas. So Bernie or Hillary or really anyone else outside of Texas, you know, I’m happy for them to do whatever they’re doing. I’m going to focus on Texas and Texans. So I really think that what’s going on in Texas right now really even just transcends party.”

O’Rourke said he is appealing to Democrats but also has had Republicans come up to him at rallies to express support. “So I did not focus on the internal Democratic divisions at the time in a year where we really all have got to come together.”

Revolution Messaging brag that they raised $218 million online for Sanders in his race for the Democratic presidential nomination. (They leave out that Sanders was challenging Hillary Clinton.) In Florida, the company had raised $8 million for Tim Canova in the 2016 election cycle. Canova is challenging former Democratic national chairman Debbie Wasserman Schultz in her reelection bid to Congress. Canova quit the Democratic Party on Monday to avoid a primary fight with Wasserman Schultz: “I am not screwing the Democratic Party. It has screwed over too many ordinary Americans and it has screwed over too many progressive candidates.” An official with Revolution Messaging said they have represented Canova in the past, but not in the current election cycle.

Already in this year’s Texas elections there has been a controversy over one Democratic candidate’s ties to Revolution Messaging.

One of the principals of Revolution Messaging is Arun Chaudhary, a videographer for Obama and Sanders who is the husband of Houston congressional candidate Laura Moser. You may recall that the Democratic Congressional Campaign Committee put out a negative package of opposition research on Moser before last month’s primary in hopes of driving her out of the Congressional District 7 Democratic runoff. The attack backfired, and now Moser is in a runoff with Lizzie Pannill Fletcher, who presumably is the preferred candidate of the national Democratic Party.

O’Rourke said it was a mistake for the DCCC to involve itself in the Houston congressional race. “You don’t need any outside interference in this,” O’Rourke said.

Sanders came to Texas just before the Democratic primary last month to give a boost to his followers who were running in Texas congressional districts and state legislative races. Only Moser and Rick Trevino in San Antonio’s 23rd Congressional District are known to have made it to runoffs. O’Rourke is not affiliated with Sanders’s Our Revolution movement.

During the 2016 presidential election, O’Rourke endorsed Clinton, but only after she captured enough delegates to guarantee she would be the Democratic nominee. However, while endorsing Clinton, he also praised Sanders. “We are fortunate to have had such a vigorously contested nomination. Secretary Clinton will be a better general election candidate and president because of the principled, passionate campaign run by Bernie Sanders,” he told the El Paso Times. “I am deeply grateful that he made campaign finance, military intervention and growing income inequality central to the Democratic nomination debate.”

After Democratic National Committee emails leaked in 2016 indicating that Wasserman Schultz had put a thumb on the party scale to help Clinton over Sanders, O’Rourke told the El Paso Times that Sanders supporters “have every right to be upset and disappointed.” He said the emails showed a disturbing lack of neutrality in the party. “It kind of shows how major party politics works on both sides,” O’Rourke said, adding that he hopes the disclosure leads to reform so that the American political system “doesn’t die of legalized corruption.” O’Rourke has said that Sanders’s campaign can be a model for his own.

Voters in both parties can be an unforgiving lot this year. Will Texas Democratic voters dismiss this as a progressive candidate using a progressive fundraising firm in a challenge to the man many Democrats see as the second most evil politician in America, or will Democratic activists see O’Rourke’s fundraising payments as going to non-Democrats who tried to invade the party in 2016 and are at least partially to blame for Clinton’s loss? It also adds fodder to Cruz’s descriptions of O’Rourke as just another Sanders-style Democrat.