"And because of this you want to junk the Constitution?"
Huh? - who said anything about junking the Constitution? Please explain what parts of the Constitution you feel are in jeopardy and by what means those parts would be invalidated.
If you are referring to the 1st amendment, please notice that the wording merely says that 'CONGRESS shall make no law' - this does not prohibit any state from enacting such laws (notwithstanding SC judicial fiat legislation).
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
As for your other comments re: Islam vs. Christianity, they are non sequitur. Islam is a cult which promotes the destruction and/or subjugation of all non-members of the cult (non-believers). The basic principals and beliefs of this cult are antithetical to a civilized, just and free society. Therefore, it cannot be allowed to continue, nor can any cult or so-called 'religion' which advocates the destruction of others. This is only common sense, not an endorsement of one religion over another.
If you believe that the Constitution forbids the states from outlawing Islam, then you must also accept that it forbids them to outlaw or regulate in any way other cults - even those which practice human sacrifice, beastiality, slavery, and other perversions, all in the name of their 'religion'. That would be suicidal for any society. Self-preservation and defense is a fundamental right for both individuals and civilized, just and free societies.
This is Madison:
Who does not see that the same authority which can establish Christianity in exclusion of all other religions may establish, with the same ease, any particular sect of Christians in exclusion of all other sects? That the same authority which can force a citizen to contribute threepence only of his property for the support of any one establishment may force him to conform to any other establishment in all cases whatsoever?
-- James Madison, A Memorial and Remonstrance Against Religious Assessments, addressed to the Virginia General Assemby, June 20, 1785
Here is Thomas Jefferson. Read and compare his vision of religious freedom to your vision of religious tyranny.
"the insertion was rejected by the great majority, in proof that they meant to comprehend, within the mantel of its protection(of religious freedom), the Jew and the Gentile, the Christian and Mohametan, the Hindoo and Infidel of every denomination."--Thomas Jefferson, from his autobiography, 1821, _The_Writings_of_Thomas_Jefferson_Memorial_Edition_, edited by Lipscomb and Bergh, 1:67
"...our civil rights have no dependance on our religious opnions, any more than our opinions in physics or geometry"--Thomas Jefferson, _Statute_for_Religious_Freedom_, 1779, _The_Papers_of_Thomas_Jefferson_, edited by Julron P. Boyd, 1950,
"I consider the government of the United States as interdicted by the Constitution from intermeddling with religious institutions, their doctrines, discipline, or exercises."--Thomas Jefferson in a letter to Samuel Miller, 1808
"(When) the (Virginia) bill for establishing religious freedom, the principles of which had, to a certain degree, been enacted before, I had drawn in all the latitude of reason & right. It still met with opposition; but, with some mutilations in the preamble, it was finally passed; and a singular proposition proved that it's protections of opinion was meant to be universal. Where the preamble declares, that coercion is a departure from the plan of the holy author of our religion, an amendment was proposed by inserting "Jesus Christ," so that it would read "A departure from the plan of Jesus Christ, the holy author of our religion;" the insertion was rejected by the great majority, in proof that they meant to comprehend, within the mantel of its protection, the Jew and the Gentile, the Christian and Mohametan, the Hindoo and Infidel of every denomination."--Thomas Jefferson, from his autobiography, 1821, _The_Writings_of_Thomas_Jefferson_Memorial_Edition_, edited by Lipscomb and Bergh, 1:67