Sorry- You are wrong.
The person in line for the Oval Office after Obama & Biden is the current Speaker of the House, in this case, Boehner. That is because the House of Representatives most closely reprsents the voting will of the people, I was taught.
The Sec of State is not an elected position—it is an APPOINTED one.
Remember how many times we here on FR got the shakes over the possibility that Nancy Pelosi could be the President if anything happened to Geo Bush?
Sec of State is probably somewhere down the line of succession, but not 3rd.
The original Constitution provides that if neither the President nor Vice President can serve, the Congress shall provide law stating who is next in line. Currently that law exists as 3 USC 19, a section of the U.S. Code. This law was established as part of the Presidential Succession Act of 1947. There, the following line of succession is provided:
Speaker of the House of Representatives
President Pro Tempore of the Senate
Secretary of State
Secretary of the Treasury
Secretary of Defense
Attorney General
Secretary of the Interior
Secretary of Agriculture
Secretary of Commerce
Secretary of Labor
Secretary of Health and Human Services
Secretary of Housing and Urban Development
Secretary of Transportation
Secretary of Energy
Secretary of Education
Secretary of Veterans Affairs
Secretary of Homeland Security
Sec of State is 4th, as specified by the United States Constitution and the Presidential Succession Act of 1947 and subsequently amended to include newly created cabinet offices.
1 Vice President of the United States (Biden)
2 Speaker of the House (Boehner)
3 President pro tempore of the Senate (Inouye)
4 Secretary of State (Clinton)
5 Secretary of the Treasury (Geithner)
6 Secretary of Defense (Panettta)
7 Attorney General (Holder)
8 Secretary of the Interior (Salazar )
9 Secretary of Agriculture (Vilsack)
... etc...