There is a reason why the Constitution can be amended. It as a very malleable document that allows changes with the times. The Constitution is something that needs to be constantly reviewed and amended, and there is no 'right time' to do so. With the growing questions regarding human rights like gay marriage, there will always be a need to review the Constitution.
Creating legislation is what the business of Congress is all about. Ideas for laws come from many places — ordinary citizens, the president, offices of the executive branch, state legislatures and governors, congressional staff, and of course the members of Congress themselves.
Moore, Gordon E. (1965). "Cramming more components onto integrated circuits" (PDF). Electronics Magazine. P. 4. Retrieved 2006-11-11.
How a Bill Becomes a Law