The entrenched old-guard Democratic Party leadership backed and elected Perez, and they don't want change. Jill Abramson hit the nail on the head with her recent piece titled, "The Clintons turned the Democratic party over to donors. Can it recover?"
To be precise, Tom Perez's assent to chair was more due to the direct hand of now former President Obama than to any apparent involvement by the Clintons. So what caused Obama to jump in and try to influence the race for DNC chair? Likely a control thing, control as in Perez being loyal to Obama and control of the Democratic Party. Perez was Secretary of Labor under Obama, and there was a chain-of-command relationship already in place. Arguably there is again, now that Perez heads the DNC.
Keith Ellison was Bernie Sanders' guy. The Democratic old guard sees Sanders as a threat, much to Bernie's delight. Bernie is not shy about his intentions. He wants reform. For starters, he wants to keep the donors at a safe distance and return the agenda to the voters. Ellison embraced that. Perez, however, thinks he can have it all ways.
Essentially, Perez's assignment is to unify and energize the base without offending the deep-pocketed campaign financiers. While naming Ellison as Deputy Chair was a nice gesture, it does little to loosen the grip on power by the established wing of the party, or to prioritize policy over fundraising. What the corporate-friendly Democratic hierarchy cannot see is the elephant on the coffee table. The base is already energized -- big time.
What the Democratic Party overlords have lost sight of is that a more dedicated, engaged base can easily compensate for the loss of a few campaign investors. Yes, there is always fear of losing campaign financing, but where are the donors getting the party now? Grassroots campaigns can and often do succeed in the face of funding deficits. The outrage is political power, though few in the Democratic old guard can see it.
Donald Trump is generating outraged Democrats, independents, and moderate Republicans at a record-setting pace. Like it or not, Tom Perez may be forced to play Uncle Tom before this is over. It's probably not who he wants to be, but if he can't stand up to the party bosses and their backers, he'll be left, as Dylan wrote and sang, "blocking up the hall " for the times they are a-changing." Tom Perez is a good man, but can he be his own man?