For the United States, it is not.
Article five of the United States Constitution.
"<span>The Congress, whenever </span>two thirds<span> of both Houses shall deem it necessary, shall propose </span>Amendments<span> to this Constitution, or, on the Application of the Legislatures of </span>two thirds<span> of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as Part of this Constitution, when ratified by the Legislatures of</span>three fourths<span> of the several States, or by Conventions in </span>three fourths<span> thereof, as the </span>one<span> or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year </span>One thousand eight hundred and eight<span> shall in any Manner affect the </span>first<span> and </span>fourth<span> Clauses in the </span>Ninth<span> Section of the </span>first<span> Article; and that no State, without its Consent, shall be deprived of its equal </span>Suffrage<span> in the Senate."
This process has happened 26 times and once unconstitutionally (the 16th amendment) for a total of 27 amendments.
To pass a law, there must be a 51% vote in both houses of Congress, and an approval by the president. Or Congress may override the veto by a two-thirds vote. This has been done well over 40,000 times in 2011 alone.
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<span>southern and eastern Europe
The reasons these new immigrants made the journey to America differed little from those of their predecessors. Escaping religious, racial, and political persecution, or seeking relief from a lack of economic opportunity or famine still pushed many immigrants out of their homelands. Many were pulled here by contract labor agreements offered by recruiting agents, known as padrones to Italian and Greek laborers. Hungarians, Poles, Slovaks, Bohemians, and Italians flocked to the coal mines or steel mills, Greeks preferred the textile mills, Russian and Polish Jews worked the needle trades or pushcart markets of New York. Railroad companies advertised the availability of free or cheap farmland overseas in pamphlets distributed in many languages, bringing a handful of agricultural workers to western farmlands. But the vast majority of immigrants crowded into the growing cities, searching for their chance to make a better life for themselves.</span>
