Dear Mr. Trump,

Apparently you didn’t get the memo – the one that told you the difference between competing in the primaries and running in the general election. Here’s the bottom line: you are now facing off against Hillary Clinton, and the media is no longer in your corner.

If you’re wondering why The New York Times ran a piece about the Khan family a full 10 days after the Gold Star father spoke out against you at the Democratic convention, even though there is no breaking news on that damaging fracas, it is because they do not want you to win. If you’re marveling at how quickly the explosive leaks about the DNC sabotaging Bernie Sanders’ campaign vanished from headlines – here it is: you are on the wrong side of the progressive press.

For months, as you duked it out against sixteen other candidates hoping to be the GOP nominee, the liberal media cheered you on. That wasn’t because they like you or approve of your message. No, they gave you enormous free air time and press because you drove ratings and spiced up what would otherwise have been a dreary march to a conventional convention. (Think Jeb Bush, non-lethal drone.)

And, they did not take you seriously; they thought you a boorish clown doubling down on reality TV. They imagined that if some unimaginable shifting of tectonic plates made you the nominee, Hillary Clinton would crush you.

Today, the liberal establishment is wary, and so the entire firepower of the mainstream media is arrayed against you. Everything you say (like your wisecrack about Russia revealing Hillary’s deleted emails) will be taken out of context and spun. Stories about GOP defections and hypotheticals about you dropping out of the race will grab headlines. The New York Times will run gratuitous stories like the recent one quoting hateful things said by people attending your rallies. There are no names, of course, no real proof that these things were said. They don’t have to supply meat; their readers will blindly consume the sauce. They won’t question why this vacuous story was published or whether the vile “kill the pigs” chants of Black Lives Matter will receive equal treatment.

The media will faithfully echo Democrat messaging – like Hillary’s line that “(You are) not someone who should ever have the nuclear codes.” This refrain will be driven home through stories like the one in Politico concluding that a president “would be free to launch a civilization-ending nuclear war on his own any time he chose.” As though you might do that in a fit of pique.

Not only will you not be treated fairly, but the media will pull out all stops to celebrate President Obama, knowing that unpopular Hillary Clinton’s best shot at winning the Oval Office is to convince voters they want “four more years.” Puff pieces that show Obama thoughtful and so disciplined that his evening snack consists of seven – only seven – almonds (New York Times) will buff his image, and by comparison spotlight just how sloppy you are.

The media will generously help Obama turn out black voters, some of whom are rightly disappointed in the past eight years. They will highlight targeted measures like Obama’s record pardoning of 214 convicts. The headlines will gloss over the reality that more than 50 of those commutations were for people convicted for firearms-related offenses, in addition to their drug crimes. Obama argues that those pardoned are part of the huge number unjustly locked up for minor drug-related offenses -- those “young people who made mistakes that aren’t that different from the mistakes I made.” This narrative is false. More than 90 percent of U.S. inmates are in state prisons; 95 percent of those locked up for “non-violent” crime have long rap sheets, averaging more than 9 prior arrests. Less than 4 percent of state-held prisoners are in jail for drug possession – and most of those have pleaded down from trafficking or are repeat offenders. Less than 1 percent of those convicted for drug-related crimes in federal courts in 2014 were locked up for possession, and generally that was the result of a plea deal.

The liberal press will extol good news about the economy, and bury the bad. The robust July jobs number got great play; near-recession level growth is ignored. They will play down the disintegration of ObamaCare, and the fraudulent Iran deal. The cash for hostages story? It will be gone within a week.

What to do Mr. Trump? Will you continue to bawl about a fixed election or whine about how people are treating you unfairly? If so, you’re doomed, and Hillary Clinton – arguably the most corrupt candidate to ever run for president, will soon occupy the Oval Office. All because you could not control yourself and could not out-think the Clinton machine.

It’s not over, but time runs short. Here is what you have to do:

1) Stay on message. Talk ONLY about law and order, job creation, illegal immigration and ISIS. That’s it. All other topics are off the table.

2) Get data points on each topic and know your facts.

3) Stop responding to ad hominem attacks. People like John Allen are looking at your campaign and deciding Hillary will win. They want to be part of that victory. Don’t take it personally.

4) Keep reminding voters of just how dishonest Hillary Clinton is. Use facts.

You can do this, Mr. Trump. Millions hope you will. Welcome to the big time.

Liz Peek is a writer who contributes frequently to FoxNews.com. She is a financial columnist who also writes for The Fiscal Times. For more visit LizPeek.com. Follow her on Twitter@LizPeek.