Democratic Party Chairman Tom Perez likes to tell people he has good weeks only when he can focus 100 percent of his time on beating Donald Trump. His two-year tenure as chairman of the Democratic Party has not had all that many good weeks.

In just the past month, he has been accused by fellow Democrats of unfairly changing debate qualifications to exclude the governor of Montana, setting thresholds that could unjustly remake the race in September, and treating elected members of Congress as “second-class citizens” by denying them a decisive nominating vote at the 2020 Democratic convention.

Nearly 100 climate change activists staged a sit-in at party headquarters Tuesday to demand a debate on the issue.

The Republican National Committee recently announced raising $75.6 million through the first five months of the year, more than twice as much as Perez’s party, with a greater share of the money coming from donations under $200.

But Perez, whose orchestration of the Democratic presidential contest will debut Wednesday with televised debates in Miami, is not discouraged. The party, he says, is on track, never mind the haters.

“Leadership is often letting down your friends at a pace that they can absorb,” Perez said during an interview in his office, decorated with photographs of his former bosses, Sen. Ted Kennedy of Massachusetts and President Barack Obama. “My goal is not to expand my holiday card list. My goal is to position our party so that we can win again.”

Among the many quirks of American democracy is the extraordinary power handed at moments of crisis to little-known party bosses. Former GOP chairman Reince Priebus, the self-effacing Wisconsin corporate lawyer, gifted President Trump a substantial general-election campaign apparatus in 2016. The last elected Democratic chairwoman, by contrast, Rep. Debbie Wasserman Schultz (Fla.), delivered to Hillary Clinton a deeply divided party, its weaknesses exposed by Russian hackers.

Unlike other former party bosses — a group that tends to draw from senators, governors and state party chiefs — Perez is a former Senate aide, Justice Department attorney and labor secretary, with only four years of elected political experience on the Montgomery County Council. But Trump’s election or defeat next year will mark Perez as either a Democratic savior or another transient bureaucrat managing a long decline.

“We lost a lot of elections that we shouldn’t have lost because we didn’t invest sufficiently in our infrastructure. We allowed politics to become transactional. We did too much mobilizing and not enough organizing,” Perez said, as the trains passed under his window on their way south over Potomac River. “I walked into a DNC that was a rebuilding job. We needed to up our game dramatically.”

At the same time, he continues to defend Obama, who never had much interest in the party apparatus, allowing it to deteriorate even as he built up a separate operation, Organizing for America. “I mean in fairness to the guy, there were two wars and a Great Recession,” Perez said. “You know — a lot of stuff going on.”

Whatever happens, no one will accuse Perez of trying to avoid conflict in the job. He is solely responsible for making the biggest decisions over how his party is approaching Trump, ordering new digital security to guard against hackers, a new data system to inform candidates — and trying to build a war room to ding Trump in local communities while the party turns inward to seek a standard-bearer in the primaries.

He also played a decisive role in remaking the nominating rules, pushing states to abandon caucuses for primaries to spur more voters to take part, making it easier to register for party membership and minimizing the influence of elected officials. He is training about 1,000 young activists to serve as the eventual nominee’s grass-roots army in swing states. And he was the one to pick Milwaukee as the site of the 2020 convention, hoping to signal the importance of the state flipped by Trump in 2016 even if it upset officials in Miami and Houston who had made a run at the prize.

Former party chairwoman Donna Brazile, who took over in 2016 after Wasserman Schultz resigned, has praised Perez for transforming himself into a politician to handle a job she calls “the worst balancing act in American politics.” In her brief tenure running the party in 2016, she uncovered what she described as an “unethical” secret party agreement that gave Hillary Clinton’s campaign some control over operational decisions in exchange for fundraising assistance during the primaries.

“On any given day there are eight people in your inbox that are screaming at you. There are several people on the phone telling you what you did wrong,” she said of the job. “He is not your typical chairman. Tom is a policy guy. He’s a geek.”

Such words of support have not kept other members of the committee from expressing their displeasure, publicly and privately. A dispute over a new data-sharing agreement between Perez and state party chairs became public last year, forcing former chairman Howard Dean to step in to calm nerves.

“There is so much mistrust between the states and the DNC after eight years of Obama,” explains Dean, who served in the job from 2005 to 2009. “I was the outsider. Nobody in Washington wanted me. It’s a very different dynamic now. Tom is the inside candidate.”

Since then a small group of committee members have repeatedly discussed the possibility of a vote of no-confidence for Perez, though several who spoke on the condition of anonymity to maintain relations with both sides said there is no current plan to take that step. The complaints range from a lack of internal communication to a failure to properly equip the party to take on Trump during the primaries.

“One of the things that he should be doing is he should be in the mud, he should be fighting back against Trump,” said Adam Parkhomenko, a former DNC field director and Perez critic, who failed in his bid for party vice chair in 2017 when Perez won. “He should be doing a lot of things that people don’t see as Nancy Pelosi’s job, and we just don’t see it.”

The criticism has been exacerbated because the RNC has transformed into a fundraising juggernaut under Trump. With so much money, the reach of the GOP election effort has also expanded. Earlier this month, the GOP began training a new class of 6,000 volunteer leaders — all of them unpaid.

Perez says he is raising enough to meet the party’s goals, and more than the party did at this point in 2015.

“The goal is not to match the RNC dollar-for-dollar,” Perez says. “We’ll never do that. I mean the RNC is a pay-to-play structure. If you look at the fundraising that occurred after the tax cut bill that passed, it was a great boon for Republican fundraising.”

Republicans, of course, hold a different view of the disparity between parties. “Tom Perez can make all the excuses he wants,” GOP spokesman Michael Ahrens said, “but his consistently weak fundraising shows how little confidence and enthusiasm there is for him and his party.”

Chris Korge, a Miami-based government relations attorney who began as the DNC finance chairman in May, said the party has needed to reconnect with Democratic donors who had grown disillusioned.

“The Democratic Party, from 2012 to 2016, did not stay on pace with the Republicans. It fell behind,” Korge said. “And now, from 2016 to 2020, we have been playing catch-up to where the Republicans were in 2016, and I assure you, we are going to catch them and pass them.”

But other donors remain concerned about the GOP advantage and the overwhelming size of the Democratic field, which could make it hard for a unifying candidate to emerge.

“The breach of trust by Debbie Wasserman Shultz has really had a long-term effect,” said Orlando attorney and party fundraiser John Morgan, who is backing former vice president Joe Biden this cycle. “That’s the real dilemma for Perez. You’ve got to have the man or woman who’s going to be the standard-bearer, and that’s when the money starts to come — or not.”

Perez has begun to tackle the size of the field by requiring much tougher qualification standards for the September debates: Candidates must have at least 130,000 donors, twice the requirement for June and July debates, and score 2 percent in four summer polls, which almost certainly will push multiple candidates from the race, making Perez even more foes.

Former congressman John Delaney of Maryland, who initially planned to self-fund much of his campaign, has been caught off-guard by the donor requirements and has written a letter demanding greater transparency on how Perez determined his plan.

“It is one of the great injustices I have seen in Democratic politics,” he said about the donor rules, which he says dismiss the voices of the majority of voters who are not in a position to give even one dollar to a campaign.

Perez is unmoved and has declined to formally respond to Delaney’s letter of protest, or similar complaints from Sen. Michael F. Bennet (D-Colo.) and Montana Gov. Steve Bullock (D), who missed the cut on the first debate after the DNC changed the polling qualifications to exclude open-ended polls. As for the protesters demanding a climate change debate, he has also signaled he will not budge. He says he told likely network debate sponsors in 2017 they needed to elevate the issue.

“Make no mistake about it, we are going to have a more robust and impactful discussion of climate change through the course of our 12 debates than ever before,” Perez said.

But that will not quiet his critics. Even allies of Perez continue to welcome a vigorous debate around his decisions. “What I tell all them is keep talking to Tom,” said Minnesota Attorney General Keith Ellison, who served with Perez as deputy chair after losing the DNC race to him in 2017. “Sometimes the answer isn’t no. It’s ‘not now.’ ”

Perez said he is ready for what is to come. “On a good day you’re going to have tension,” he said. “I didn’t walk into the DNC on a good day.”

Michelle Ye Hee Lee contributed to this report.