How has the relationship between presidents and Congress changedwith respect to the legislative process since the founding?

What will be an ideal response?

An ideal response will:
1, Explain that while the Constitution seems to give primary responsibility for lawmaking to Congress,over time the initiative for proposing big legislative programs has shifted to the presidency.
2, Discuss the relevancy of the State of the Union and the Budget Act of 1921 as factors that have facilitated this shift in power.
3, Note that while Congress still retains ultimate legislative authority, it often now waits for presidential action and then responds to that action; for example, in the cases of the New Deal, the Fair Deal, and the Great Society.