DW: President Donald Trump has been in office now for six months and it is fair to say that it has been a very rocky half-year. As his biographer you already had deeper insights into Trump than the general public. Did you expect things to turn out the way they did or did the first six months of the Trump presidency surprise you too?

Gwenda Blair: In one word - no. I don't claim to have a crystal ball, but I don't think one needed one. The kind of proposition that he made was that he would bring his business experience to the White House. And people thought that meant that he would use it on behalf of the country.

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I think he has brought his business experience to the White House, but he has used it on his behalf. He had a for-profit brand-building business and now he has made the White House a for-profit brand-building operation. And so in that sense, I don't think it is surprising.

One striking characteristic of his presidency so far is Trump's reliance on family members to run the White House, much in the same way they helped him run his campaign. His close ties to family members have caused political and legal problems for Trump, most recently when it was revealed that his son had met with a Russian lawyer during the campaign. But Trump so far has always defended his family. Do you see anything that could cause him to cut loose and disavow his family members?

I think this could be the only true crisis for him that might come up in his presidency. He expected he could run the White House and the country like a business. If you tell people to do stuff, they do it. But it turns out that he is facing a Congress with 535 people who have their own power bases and they don't really snap to. I think this has been and is a continuing shock for him.

Blair: Trump is turning the White House into a 'brand-building operation'

But considering throwing somebody named Trump or somebody married to somebody named Trump under the bus - that could be a real crisis. But so far, I don't think, as far as he is concerned, there has been any crisis. He moves the goal posts and redefines the goals constantly, for example on healthcare, and says, "This is what I meant. Why isn't this successful?"

Another feature of his early tenure is an apparent lack of strong political convictions even on crucial issues like climate change, healthcare or trans-Atlantic relations and instead a focus on deal-making even without clear outcomes in mind and at the risk of alienating partners and cabinet members. Can you explain this characteristic of Trump?

He spent his entire life being extremely competitive and absolutely laser-focused on winning. All that matters is winning or losing and he is always going to win. And if you can't win one way, you win another way.

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Early on in his career in his first big project with his name on it, when he was marketing condominiums in Trump Tower in New York, he was very unhappy with the fact that a scale model of the General Motors building next door was taller than Trump Tower.

So he wanted to make Trump Tower taller in the scale model, but the woman in charge of sales said, "You are not allowed to do that." So what he did was make the other building shorter. He couldn't make his building taller, but the other building shorter. He was allowed to do that. That encapsulates how everything gets done.

Firing Comey was 'a very, very big deal,' says Blair

Some of his defenders have argued that Trump is a political novice and needs time to adjust to his new role as president. With Trump in office for six months now, do you expect him to change his behavior?

Not a bit, not a bit. A political novice? He is 71 years old and has been a citizen of this country for, I believe, all 71 years. We are all taught in civics that there are three branches of government, checks and balances and that you have to compromise.

But that's not what he did in business. In business, he would get the person in the room, beat up on them and get as much as he could and leave them as little as possible. So why would he change? I don't see that happening.

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Also he has that big enough base and the one thing he has delivered on is that he promised he would make a big mess in Washington and turn it all upside down - and he has delivered. His base doesn't seem unhappy.

Since you say we should prepare for things continuing the way they have been, what is your advice on how to deal with President Trump?

I think the media and the country need to keep two things in mind. Follow his tweets and his distractions because they have to be followed to be responded to, but never take your eyes off what else is happening in Congress, in other parts of the executive and never lose track of those. He is not getting anywhere legislatively, but an awful lot of stuff is happening across the rest of the federal government which is very large.

And finally, if you had to name the three most significant incidents during Trump's first six months in office what would they be?

At the moment a few things that could be history book items are firing Comey, a very, very big deal, and his insistent support for autocratic figures, including [Russian President Vladimir] Putin most notably, but not just him, and his inability to get anything done.

Gwenda Blair is the author of "Trumps: Three Generations That Built an Empire" and "Donald Trump: Master Apprentice." She teaches journalism at Columbia University.