This president towers over the Democratic Presidential President of 2020.

No, not President TrumpDonald John TrumpTrump says that Warren is more interested in her heritage & # 39; must then focus his businesses to investigate Trump: people say that wall has made no difference in El Paso's & # 39; full of mess & # 39; GOP promotes Trump line with campaign slogan from Hillary Clinton 2016 MORE.

I'm talking about President Obama.

Obama left office with an approval rate of 59 percent and a disapproval of 37 percent, according to Gallup.

At the end of January, Gallup's polls for President Trump were exactly the opposite of Obama's number – 59 percent disapproval and 37 percent approval.

A poll of July 2018 from the Pew Research Center showed that 31 percent of Americans call Obama the best president of their lives. Nearly half of Americans, 44 percent, even said that Obama is the best or second-best president they've ever known.

While the Democrats are starting their campaign for the party's nomination in 2020, Obama is the unparalleled power broker of the party.

He will be the biggest speaker during the 2020 convention of the party.

His wife, Michelle ObamaMichelle LeVaughn Robinson Obama The Hill's 12:30 Report – Presented by Kidney Care Partners – Negotiators want to revive revived border talks The Hill's Morning Report – Presented by the American Academy of HIV Medicine – Next 24 hours critical for stalled financing talks Juan Williams: Obama-casts long shadow over 2020 MORE, perhaps the second-largest.

Her book & # 39; Becoming & # 39; has been the best-selling book in the country for the last three months. If she ran for the nomination of her party, it would be difficult to stop her. Even the Trump-friendly Rasmussen poll shows that she beats the current president during a general election.

And do not forget that President Obama is releasing his own book about his time at the White House. It will probably be published in the heat of the 2020 campaign. He will have a huge national platform and every reason to finally abandon all reluctance and fight against Trump.

Just seeing him will give Democrats a boost. He is a striking contrast to Trump's era of alleged gains for porn stars, chaos in the White House and accusations of collusion.

In a Democratic primary that will almost certainly have more than a dozen candidates, Obama will be anointed – if he gives approval – to become rocket fuel for one lucky candidate.

How times change.

Obama was not always the most left-wing hero.

They complained that the first black president was so afraid of being labeled as a black radical that he moderated liberal policies and dampened his answers to GOP obstruction.

Now, with Trump as president, those same liberal votes are being raised to defend Obama's record.

Trump eliminated them by attacking Obama's policies while respecting the results.

The strong economy and the low unemployment rate?

They are largely a continuation of Obama's successful economic policy, which brought the country back from the Great Recession.

As the Washington Post noted at the end of last year, "the economy" added more jobs to Obama's second term every year than in the first year of Trump. "

Do you go after ISIS and other Islamic terrorists?

Obama had demoted them with drones and special forces before Trump became president.

And what about Trump's attack on ObamaCare, without producing a better plan?

Congressional Democrats are in charge of the House of Representatives because they campaigned in the meantime as fans of ObamaCare and its protection for people with pre-existing conditions.

Each of the Democratic presidential candidates from 2020 defends the "Affordable Care Act", while several calls up to Medicare for All & # 39;

It is difficult to name a Democrat who is running for the nomination that is not part of Obama's legacy.

Former Vice President Biden is the main candidate for the nomination because of his eight years as Obama's deputy.

Sen Kamala HarrisKamala Devi HarrisPress: Democrats dare to think big Buttigieg on Trump: "I am a homosexual man from Indiana, I know how to deal with a bully" & # 39; Klobuchar will not take corporate PAC money for the success of presidential campaigns MORE (D-Calif.) As a prosecutor led the late journalist Gwen Ifill to describe her as "the female Barack ObamaBarack Hussein ObamaJuan Williams: Obama casts a long shadow over 2020 Let's look at factors that are favorable to Dems in 2020 Chris Wallace: Rich & # 39; Rich & # 39; for GOP to train against the inattention of the Demons after repeated investigations from the era of the era. Now she follows in his footsteps as first-term senator walking in front of the White House.

Julian Castro became a national political figure when Obama tapped him to give the keynote speech at the 2012 Democratic National Convention. Obama later called him his second secretary from the Department of Housing and Urban Development.

Sen. Elizabeth WarrenElizabeth Ann WarrenTrump says that Warren is more interested in her heritage & # 39; must focus then investigate his businesses Press: Democrats dare to think big Buttigieg on Trump: "I am a homosexual man from Indiana, I know how to deal with a bully & # 39; MORE (D-Mass.) Was an academic when Obama named her to monitor the federal government's response to the global financial slump of 2008. She later worked with congressional Democrats to create the Consumer Financial Protection Bureau.

Sen Cory BookerCory Anthony Booker Please tap on Trump: "I am a homosexual man from Indiana, I know how to handle a bullying & # 39; Cuomo to meet Trump through SALT deduction hood. Demanalist says that Fairfax accusations should be checked before calls are made for him to resign. MORE (DN.J.), another ally of Obama, is constantly being compared to the 44th president.

The upcoming campaign is a battle between political poles represented by Obama and Trump.

On the one hand, Trump's profession is based on fear and grievance – for example on immigration. On the other hand, the Democrats return to Obama's characteristics of hope and change – for example, by creating a better health system.

In his farewell speech, Obama rolled the answer of his party to Trump:

"If you're tired of arguing with strangers on the internet, try talking to one of them in real life," Obama said. "If you are disappointed by your elected officials, grab a clipboard, take some signatures and walk to the office yourself, show up, dive in. Stay with it."

For every Democrat, the bottom line to win the nomination is convincing co-Democrats who beat them with Trump.

But first they have to convince Obama.

Juan Williams is an author and political analyst for Fox News Channel.