Julian Zelizer , a history and public affairs professor at Princeton University and a New America fellow, is the author of " The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society. " He's co-host of the "Politics & Polls" podcast. The opinions expressed in this commentary are his own.

(CNN) President Donald Trump doesn't care what the experts have to say. "No matter how much I accomplish during the ridiculous standard of the first 100 days, & it has been a lot (including S.C.), media will kill!," he tweeted.

While his critique of the concept of the first 100 days might be fair, it is hard to look at how Trump has performed in the first months in office and not conclude that he and the Republicans face a serious problem.

He doesn't have any major legislation to speak of. The only significant bill he attempted to move through Congress, the repeal and replacement of Obamacare, collapsed under the weight of conservative opposition. He's attempting to revive it , but chances are dubious. His travel ban executive orders stalled twice in the courts.

On foreign policy, he has flipped and flopped without any major diplomatic or military breakthroughs. He has stimulated an energized opposition movement that has caused Republican legislators attending their own town halls to think twice about supporting anything that he says. Throughout everyday of this period a major scandal involving collusion with Russia in the election has loomed over his actions.

Just maybe, however, the failures of these months are not as devastating as some might think.

The first 100 days is a construct , an artificial period of time that doesn't have any intrinsic meaning but is routinely used to grade presidents. There have been presidents such as Barack Obama (on health care) and George W. Bush (counterterrorism programs) who have done big things after the 100 days are over. Richard Nixon went to China in 1972, a visit that defines his presidency in some ways. There have also been presidents such as Jimmy Carter who earned high marks for accomplishments during the 100 days only to struggle for the remainder of their presidency. If Trump and the Republican Congress are able to move legislation in the coming months, the failure won't be that important in defining his legacy.

Normalizing the presidency?

And notably, the normalization of a presidency that seemed so tenuous in January is an accomplishment in itself for Trump. With many observers wondering if he would be able to handle the day-to-day challenges that come with the job and whether he would last for very long with his twitter-storms and tirades, it is worth noting that as we enter into the summer most of the discussion now centers on what comes next with his policy agenda. What will he do with North Korea? How will he handle relations with China? Can he move forward with tax reform or an infrastructure package? The shift in discussion has been a remarkable turn of events for this controversial former reality television show star. All the talk about the conflict of interest with his family business and new political business has generally subsided.

And the normalization has occurred with a massive unresolved scandal centering on the possibility of a thrown election in coordination with the Russians. This is serious stuff. The accusations that have emerged about what happened in the 2016 campaign have not abated. Indeed, they have only become worse. There have been steady drips of evidence coming out about the connections between different Trump campaign officials and the Russians -- all the while the intelligence agencies are in strong agreement that the Russians did intervene in the election through hacking and fake news.

This is the kind of scandal that could make Watergate or Iran-Contra look like child's play. Yet, at least thus far, he has survived. Partisan loyalty has protected the administration in the House where the Intelligence Committee investigation initially seemed to have broken down. Other than a handful of voices in the Senate, such as John McCain or Lindsey Graham, there has been notable silence within the GOP about all the evidence that has emerged. This scandal could still get much worse, but at least at the close of the first 100 days Trump is still standing and the national conversation has shifted to other issues.

We are now back in the realm of learning about behind-the-scenes power struggles , the normal grist of presidential politics. One of the measures that matters to him, and to many of his Republican supporters, is how the economy is doing. They will find relief from the fact that the stock market remains strong and the major economic indicators continue to move in the right direction. That might be the work of President Barack Obama, but Trump can easily point to it as proof the nation is strong.

Trump's agenda

The administration has been able to destabilize the standing of the media. Trump's incessant attacks on news organizations as "fake" and his ability to flood the country with misleading or false statements via Twitter and his advisers have made it more difficult for Americans to tell the difference between fact or fiction.

He has built on trends that have been gathering strength over decades, such as the increasingly partisan news and distrust in the media, to undermine confidence in what people hear from established sources. In this kind of atmosphere, it is easier for the President to shift the national agenda to new issues and confuse public understanding of what is going on. Reporters are having difficulty serving as "watchdogs" when more people don't believe what they are saying.

Executive power, though not as long-lasting as legislation, has served as a potent tool in Trump's arsenal. At the same time he has shown almost no interest in working on legislation or even engaging members of Congress, he has tapped into his CEO instincts by using executive orders with increasing ferocity.

While the ban on refugees stalled in the courts, other measures such as accelerated deportations and deregulations of energy markets have moved forward at a Rooseveltian pace. He has staffed many key agencies with top opponents of the programs they now run. Senate Democrats were unable to stop the confirmations. The measures will have a big effect on the lives and industries being regulated, while his appeals to the mainstream Republican Party -- at the same time he drops his populist facade -- will shore up his support with Republicans.

The confirmation of Neil Gorsuch for the Supreme Court was a major success for a President who has been promising since day one he would deliver a more rightward court. Though Democrats have been competitive in some of the special elections that have taken place, at least thus far they have not been victorious, suggesting that some of the anticipated electoral gains might be more limited.

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According to CNN, Trump has also been raising tens of millions of dollars for a re-election bid in 2020 , including 7.1 million for the Donald J. Trump for President Inc. This means he can easily command a formidable war chest going into the primaries that would scare off any Republican challengers and create immense pressures on a Democratic opponent. The numbers should not be taken lightly.

Still Trump can't be boasting about what's happened since January. In the list of presidential 100 days, his will be low on the list. If he wants to be part of the pantheon of productive presidents, there is no way to make that case convincingly.

His opponents though shouldn't be so confident either since a closer look at what's happened since inauguration suggests this President might be in much better shape than they think, with a lot of time still left on his political clock. For those who initially asked if impeachment or resignation would happen soon, they might start thinking about what the odds are for a second term.