Julian Zelizer is a professor of history and public affairs at Princeton University, and author, with Kevin Kruse, of the new book " Fault Lines: A History of the United States Since 1974. " Follow him on Twitter at @julianzelizer. The opinions expressed in this commentary are his own. View more opinion at CNN.

(CNN) Many political observers are struggling to figure out what the President's game plan is for 2020, and no wonder: This week was hard to believe. The President announced that he would support new health care legislation to replace Obamacare, but then backed away when congressional Republicans said no.

Although Trump initially supported the full release of the Mueller report, the President shifted gears, suggesting he would be open to its remaining private. He shows no interest in stepping back from his fights with the Democratic House. He continues to accuse them of "presidential harassment" as they seek the Mueller report, his tax returns, testimony about the decisions behind the granting of White House security clearances and more.

He told the NATO secretary general that his father was born in Germany, which he was not. After threatening to close the southern border, which would cause economic havoc, he said he will instead hold off for a year.

Then there was the speech to the National Republican Congressional Committee, when President Trump baselessly suggested that noise from wind turbines causes cancer and went on to predict that his remarks -- which were being broadcast on C-SPAN -- would be leaked.

His rallies, as an article in the Atlantic explains , have been a smorgasbord of one-liners and disconnected rambling. "Recent appearances seem untethered to any sort of strategy to drive a policy agenda ahead of the 2020 presidential election," writes Peter Nicholas.

With all this chaos, what is the President's strategy for winning re-election?

In fact, chaos is the strategy. Using it, President Trump hopes to defeat Democrats in a massive game of prevent defense.

Trump has always perceived the news media to be the central arena through which he fights his battles. An avid consumer of cable news and now a social media fanatic, the President has been less interested in old-fashioned grassroots electoral work than in dominating the national agenda. His rallies are more about putting on a show for the cameras than in making sure his support on the ground is solid.

The President intends to use his mastery of the media cycle to totally control the agenda throughout the next two years, making it difficult -- if not impossible -- for Democrats to discuss their own ideas.

Even the ongoing controversy over seeing the Mueller report continues to push away opportunities for Democratic candidates to debate policy issues.

At some level there is a logic to such a plan. After all, Democrats are on strong ground when it comes to a large number of policies -- health care, climate change, gun control -- and more. Given the President's low national approval ratings, there is also a good chance that the Democratic candidate will be seen in a more favorable light than the President. But if they get drowned out by coverage of Trump, that's better for the President.

Trump will do everything possible to keep Democrats out of the media other than in the light he wants to paint them. As he has done since day one in the Oval Office, Trump will continually blitz the nation with controversy, inanity, outrage and fierce polemical attacks so that in each minute of the day reporters, producers, editors, bloggers and tweeters can't resist offering some kind of response.

And Trump has one major advantage over most of his competitors. He is willing to say almost anything -- true, twisted or totally false -- to gain attention. He lacks the restraints that still keep many other politicians in check.

Trump's chaos will make the media playing field rough for Democrats. They will need to figure out a way to cut through the President's noise and to steal attention away from the shiny object that is the President of the United States.

Democrats will have the extraordinarily challenging task of restraining themselves from always being the position of reacting to what the President has to say or they will risk drowning their own campaign strategy and message. Democrats might have more popular policy stances and a candidate with higher favorability ratings -- but the impact will be diminished if they get lost in the Trumpian frenzy.

It is far from clear that the President's chaos strategy is a path to easy re-election. After all, he is playing prevent defense even though he is not ahead in the score. Yes, he is the President of the United States and that counts for a lot politically. But his national standing is extremely weak, his legislative record remains thin, and Democrats showed in the midterms the kind of electoral gains they can secure if they handle the challenge the right way. He is riding a very strong economy, although there has been growing evidence of underlying weaknesses such as slowing job growth in the manufacturing sector.

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Democrats might decide to double down on old-fashioned organizing and grassroots work if they determine that there will simply be a limited opportunity to inject their candidates into the national media conversation. Or the primaries and caucuses might produce a winning candidate who has a vision of how to be heard over the President's rhetorical bombs. But one thing is clear, the chaos strategy can be extremely effective, and Democrats ignore it at their peril.