Why do we study election based both on swings AND trends?

[Matty]

This might be a dumb question, but what does a trend tell you that a swing does not?

[justfollowingtheelections]

This might be a dumb question, but what does a trend tell you that a swing does not?

Trends try to "normalize" the swings by taking into account the national performance of the two candidates.  If for example Obama beats McCain by 7 points, obviously a lot of states will swing Democratic, but was that swing because the candidate was very strong or because the state is generally more Democratic than before?  Trends in other words "clean up" the data by removing the strengh or weakness of the candidate from the equation (to some extent because some candidates are very strong or very weak in certain states only, not nationally and that skews the data, see Trump's performance in Utah).  But overall trends give us a better picture than swings.  I hope that helps!

[Young Conservative]

This might be a dumb question, but what does a trend tell you that a swing does not?

Trends try to "normalize" the swings by taking into account the national performance of the two candidates.  If for example Obama beats McCain by 7 points, obviously a lot of states will swing Democratic, but was that swing because the candidate was very strong or because the state is generally more Democratic than before?  Trends in other words "clean up" the data by removing the strengh or weakness of the candidate from the equation (to some extent because some candidates are very strong or very weak in certain states only, not nationally and that skews the data, see Trump's performance in Utah).  But overall trends give us a better picture than swings.  I hope that helps!

This is what's known as the perfect explanation of something. A very rare occurrence in the wild (Atlas)!

[Del Tachi]

I've always wondered, how are trends done for the gubernatorial/Senate races?

Are they compared to the national-level swing?  or the state-level swing?

[Bismarck]

I've always wondered, how are trends done for the gubernatorial/Senate races?

Are they compared to the national-level swing?  or the state-level swing?

And are the senate swings from six years ago or the most recent senate election?

[AGA]

I've always wondered, how are trends done for the gubernatorial/Senate races?

Are they compared to the national-level swing?  or the state-level swing?

And are the senate swings from six years ago or the most recent senate election?

I believe that they factor in all the Senate races nationwide from six years ago.