President Donald Trump’s speech kicking off his reelection campaign Tuesday made clear how he thinks he can win: through scorched-earth negativity and the politics of resentment.

Speaking in Orlando, Florida — and mostly reading from prepared remarks rather than improvising — Trump launched attack after attack on familiar hate figures: Democrats, the “fake news,” the Mueller investigators, and, of course, Hillary Clinton.

“Our radical Democrat opponents are driven by hatred, prejudice, and rage and want to destroy you, and they want to destroy our country as we know it,” Trump said.

The speech actually opened on a positive note. Trump thanked his supporters, said he’s restored “government by and for the people,” and bragged about the economy’s performance.

Then, just about five minutes in, things took a turn.

“2016 was not nearly another four-year election. This was a defining moment in American history,” Trump said. Then in a mocking tone, he gestured toward the members of the media present and said: “Ask them, right there.” In case anyone missed his meaning, he added: “By the way, that is a lot of fake news back there.”

Chants of “CNN sucks” resounded among the crowd.

Soon afterward, Trump trashed special counsel Robert Mueller’s investigation (“an illegal attempt to overturn the results of the election”), “crooked” Hillary, and the Democrats (“depraved,” “unhinged,” “radical,” “extreme,” “dangerous”).

A Democratic win in 2020, in Trump’s telling, wouldn’t be an ordinary political outcome. It would be the end of the world.

“They would shut down your free speech and use the power of the law to punish their opponents,” he asserted. “They would strip Americans of their constitutional rights while flooding the country with illegal immigrants.”

Trump has not been polling well

The context is that Trump began his presidency in a tenuous political position, elected quite narrowly and likely needing to at least equal if not improve his support to win in 2020 — and has seen his popularity worsen since.

Trump lost the popular vote to Hillary Clinton by 2.1 percentage points (she got 48.2 percent of the vote, he got 46.1 percent).

His narrow Electoral College majority hinged on margins of less than 1 percent in three states: Wisconsin (0.77 percent), Pennsylvania (0.72 percent), and Michigan (0.23 percent).

Over the past year, more than 50 percent of respondents in national polls have consistently said they disapprove of Trump’s presidency, and his approval rating has been down in the low 40s.

And in 2020 polling, he has consistently trailed several leading Democratic candidates both nationally and in swing states.

All this is hardly a surprise given Trump’s longtime preference for retaining the support of his “base” through polarization and division, rather than trying to unite the country or reaching out to people who don’t already support him.

However, this is more or less how Trump beat Clinton in 2016. Polls showed he was the most unpopular major-party presidential nominee ever, as measured by favorability ratings. But Clinton became the second most unpopular, and it turned out that just enough people in the key swing states ended up turning out for Trump rather than Clinton.

So this points to Trump’s likely best hope for reelection. He is too toxic to hope for a landslide. But it’s certainly conceivable that he could make the eventual Democratic nominee toxic to enough voters that he can squeak through with another narrow win.

Broadening his support would be nice — but he seems more focused on making sure Democrats don’t broaden theirs.

Still, some parts of the speech came off as rather old hat.

In particular, Trump returned again and again to attacking Hillary Clinton, weaving together her email scandal, her campaign’s funding of the Steele dossier, and her use of the word “deplorables” to describe some of Trump’s supporters. He mentioned her eight times in about 80 minutes.

Clinton, of course, will not be on the ballot in 2020. So though Trump did his best to demonize “Democrats” generally and the media, he is still lacking the personal foil on which he usually prefers to rely. He gave brief mentions to “Sleepy Joe” Biden and “crazy” Bernie Sanders but didn’t dwell much on them just yet.

To truly make his reelection case, that’s what he’ll have to do: figure out how to destroy the Democratic nominee.