ELEANOR HALL: When George W Bush was president, he also had some battles with the courts. Alberto Gonzales served as President Bush's Attorney General.

He is now the Dean of Law at Belmont University and he joined me this morning from Nashville.

Professor Gonzales, thanks so much for joining The World Today.

ALBERTO GONZALES: Happy to be with you.

ELEANOR HALL: Now, Vice President Pence says that President Trump is on solid constitutional ground with his executive order on immigration. Your view?

ALBERTO GONZALES: Well, I think it's a somewhat more complicated question. I think if I were working in the White House I'd feel a little bit more comfortable if two additional conditions existed.

One - if the Congress had passed a specific law authorising or giving the president discretion to do what he has done through this executive order, and/or two - if there was evidence of some either attack or a threat from one of these seven countries. Otherwise, if there's not such a threat, one might have to ask what is the basis for choosing these seven countries? Is it based solely on race or religion?

And if that's the case, I think that the President may be on less solid ground. So, if the conditions were different I would feel more comfortable. I'm not suggesting that Vice President Pence is wrong. As a lawyer, you want to be, you know, as sure as possible in advising a client, and I think there would be some conditions that would, I think, make the executive branch's position much more solid.

ELEANOR HALL: And you say that it also would make a difference if Congress had passed a law. Are you suggesting that an executive order is not as strong as an order from, or a law from Congress?

ALBERTO GONZALES: No, it is not. It is simply the executive acting on his own. Historically, the courts are more deferential when the president is acting on his own authority, combined with some kind of grant of authority from the Congress.

You know, you always try to find ways to put the president in the strongest position possible as you go into a fight in our courts.

ELEANOR HALL: You were the attorney-general of the United States under George W. Bush. The Bush administration also faced some tough battles with the courts. Anything like this?

ALBERTO GONZALES: Well, of course, yes, we faced some very tough battles in the courts. I can't recall there being anything quite like this, this subject matter, but obviously many of the terrorism issues that we had to...that we dealt with following the attacks of 9/11 - and I must say that Australia was a tremendous ally to us, and we will always be grateful for that.

But clearly, you know, in a time of war, I think the president is given greater discretion. So, following the attacks of 9/11, president Bush was given greater discretion.

But nonetheless, the courts existed as a very valid check on President Bush, as they should. That's what we have in our system of government - we have checks and balances. We have three co-equal branches of government, each checking each other in their own specific way as granted under the Constitution of the United States.

ELEANOR HALL: Now, you say the courts are the final arbiter. There have been multiple court cases on this, even within this short space of time.

The President is clearly unimpressed with the failure of the courts to back his executive order, tweeting today that the federal judge in Washington state who blocked his executive order on Friday was only a "so-called judge".

To what extent does this sort of disrespect for a judge from the President of the United States concern you?

ALBERTO GONZALES: Yeah, I would not have been critical of a judge as President Trump was. You know, I just think that, quite frankly, it's not something that I would do and it's not something that I don't believe that President Bush or the Bush administration would ever do.

We, of course, took issue with this, with previous decisions by our courts, but we always tried to be respectful. If you disagree, you say, "I respectfully disagree and we're going to appeal the decision". I think that's the way that I would've handled it.

ELEANOR HALL: I've spoken to some other legal experts who've warned of a constitutional crisis if the President were to instruct border control officers not to follow the court's orders. Is that something that concerns you?

ALBERTO GONZALES: No. I think we're a long way from that. I have every expectation that when the courts finally speak that the President's going to abide by the court's decision.

And I've heard some people say that this is like President Nixon and all that. But, you know, President Nixon took action to further his own political and individual wrongdoing, and this is far from that.

Here, President Trump, I believe, is trying to protect our country, and we're now going to get this resolved in the courts.

ELEANOR HALL: But with the President making these statements disrespectful of judges, doesn't that decrease the authority of the courts in the public's mind?

ALBERTO GONZALES: Well, clearly, when the President criticises a judge, it is a little bit different than when a normal citizen criticises a judge, but nonetheless, judges do enjoy lifetime tenure for the very reason that the framers of our constitution intended to protect them - to have them immune from such criticism.

I take your point that some people may be affected - their judgment or opinion of our courts may be affected by what the President of the United States says. And for that reason we would not, the Bush administration, would not have said what President Trump tweeted. I certainly wouldn't have said that. As I said, we simply would have said, "We're gonna appeal the decision".

ELEANOR HALL: If the authority of the courts is lowered in the minds of the public, is that something that would concern you?

ALBERTO GONZALES: Of course. Of course. That is something that would concern me. But at the end of the day, the courts need to continue doing their job and again, that's just the way that our system operates.

ELEANOR HALL: So, now, what is the status of this executive order? Will it end up in the Supreme Court, do you think?

ALBERTO GONZALES: I think it's very likely, given the public position of the administration. I think that they believe that they are in the right.

Now, your listeners need to understand that there has been no decision on the merits, as of yet, and so there's going to briefing, briefs filed with the Ninth Circuit today, as I understand it, and then the government will have a chance to respond tomorrow. So, as of yet, there's really been no briefing, no papers arguing the merits with the courts that have been filed yet, and so I think the Ninth Circuit will make a decision here, and then the government may decide to go ahead and take that to the US Supreme Court.

I don't know whether or not the court will take up the case, simply because, typically, the Supreme Court likes to receive a case after it's been fully briefed and fully argued all the way up from the district court level, to the circuit court level, so, you know, I can't speak for the court, but it remains to be seen whether or not this ultimately is going to be resolved by the Supreme Court.

ELEANOR HALL: If the Supreme Court, as you suggest, does refuse to take this case until it's been worked through some of the lower courts, how long could that take?

ALBERTO GONZALES: Oh, it could take, it could take months. There's no question about that.

Now, there may be means of expediting cases, but nonetheless it's going to take some period of time. There are measures already in place to protect America, and so what the United States government has asked for is the authority, or the ability to impose even greater vetting in place.

And so, you know, the fact that we have something in place already to protect America may reassure our courts that, sort of, take the time to get it right.

ELEANOR HALL: And if the Supreme Court does end up hearing this case, we have a new Supreme Court judge there as of last week. Do you think that that would give the President, or should give the President, confidence that the court will rule in his favour?

ALBERTO GONZALES: Well, this new judge is only nominated by the President last week. He probably will not be on the bench until April. You know, there's all kinds of possibilities in terms of what may ultimately happen.

I don't think though, even if Neil, if Neil Gorsuch were to hear the case, given what I know about Judge Gorsuch, I don't think his decision or outcome is going to be affected in any way by virtue of the fact that he was nominated by Donald Trump.

I have every confidence that Judge Gorsuch will simply look at the law, look at the facts and make a decision as to what the Constitution demands.

ELEANOR HALL: Professor Gonzales, thanks so much for joining us.

ALBERTO GONZALES: Thanks for having me.