Should the US halt tourism and business travel from the European Union?

Short answer: No.

Long answer: Hell no.

With respect what will be your answer if ISIS succeed and thousands die. ISIS is far more fanatical with finances that run into billions than the group who carried out 9/11
Will the long answer then be f*****g hell why was the government not prepared?

I don’t see why this would be that difficult. You can start by asking people to self-report, or by banning people from countries with a high proportion of Muslims. Or you could do what the Japanese did for a couple centuries when they (mostly) banned Christians, they required them to desecrate the crucifix before they were allowed to enter. It obviously wouldn’t reduce Muslim immigration to zero but it would certainly decrease it.

There are also a number of other countries (Poland, Hungary and I believe the Czech Republic) that currently are trying to limit Muslim immigration to near-zero, so Trump isn’t alone here by any means.

I would agree it’s immoral and unethical, but it’s probably not Unconstitutional. (unless they are US Citizens)
http://blogs.wsj.com/law/2015/12/08/is-trumps-proposed-ban-on-muslim-entry-constitutional/
Constitutional challenges to immigration restrictions “face unusually tough hurdles,” *Stephen H. Legomsky, of Washington University School of Law, who was chief counsel at the U.S. Citizenship and Immigration Services agency under President Barack Obama from 2011 to 2013. Most recently the professor served briefly as senior counselor to the Secretary of Homeland Security on immigration issues.

The hurdle he referred to is in the form of the so-called plenary power doctrine, a legal concept articulated by the Supreme Court giving Congress tremendous power over immigration laws. It was first laid down by the Supreme Court in the late 1880s when justices upheld the Chinese Exclusion Act, a federal law that suspended immigration of Chinese laborers. Repealed during World War II, it was the first major immigration restriction enacted into law and the first exclusion based on ethnicity.

The plenary power doctrine “states that the courts should show exceptional deference to Congress when it legislates in the field of immigration,” Mr. Legomsky told Law Blog. “Whether modern courts would uphold a racial or religious immigration restriction is difficult to predict.” The high court has reaffirmed the doctrine in a 1972 ruling denying entry to a self-described “revolutionary Marxist” from Belgium who sought a temporary visa.

UCLA law professor Eugene Volokh told Law Blog that Mr. Trump’s plan “may be a very bad idea, but under the plenary power doctrine it may very well be constitutional.”*

Why?

It’s against my morals and ethics to discriminate against someone based solely on their religion. It’s Ok by yours?

Fascinating. Can you describe the measure that Poland, Hungary and you believe the Czech Republic are taking? Do they involve requiring travellers to desecrate the Koran, or to declare their religion?

Yes, it is. Religious thought and action is no more sacrosanct than secular thought and action. A person should be judged by the quality of the groups they choose to align themselves with, even if the group uses “God says we should…” as a prefix. Even if Islam as a whole does not fail to meet that standard (and I agree it doesn’t), even if particular sects of Islam like Wahhabism do not fail to meet that standard, there have been religions founded on the literal belief that mass murder is necessary for the continued existence of the world. Hell, even the Jews believe that mutilating the genitals of infants is a necessary part of their religion.

Under the First Amendment, the fact that a group is a religion should not be held against them, but neither should it be a point in their favour.

I mean, yes, in the abstract? If I were going to design an ideal country, it would be an officially Christian state with preference for Christianity and maybe a few other favoured religions. But more particularly, when it comes to people who live in your country. I don’t know even many liberals who would say if anyone wants to come live in your house, you should let them. Why would it be different when it comes to living in your country?

Discrimination properly refers to what sort of distinction we make between different members of our political community, not who’s allowed to belong to the community to begin with.

Living in your house isn’t the same as living in your country. In your house, your rules apply. Making laws for a country isn’t the same, and if you’ve spent some centuries telling the world you believe in a set of values embodied in a state of law, and then decide those values suddenly exclude a whole class of people, irrespective of their individual merits and behaviours, it doesn’t do you any favours.

It’s irrelevant whether the Constitution applies to visiting foreign nationals, because it definitely applies to the US Congress, and it’s Congress that would have to pass any of these immigration policies.

And Trump can’t have meant “until we have the proper security in place”, because we already do.

It’s irrelevant what you think the Constitution says. SCOTUS says Congress has the power to bar foreign nationals from entering the country on almost any grounds. It’s pointless and stupid, but it’s not unconstitutional.

It’s not enough to bam Muslims (even temporarily.)
You need to block the Internet from abroad too, since the director of the FBI visited Colorado this week and detailed how the terror organization ISIS is recruiting Americans to take up their cause.

The founding fathers are rolling in their graves.