US Election Vocabulary: Moving the needle?

The expression “moving the needle” first appeared in England during the industrial revolution.  The reference was to gauges on steam engines.  During World War II, it became a more common term in reference to aviation gauges.  In business today it’s synonymous with making progress. Source
In US politics to 'move the needle' is to significantly change the opinion polls in the direction of your candidate. So far in this election cycle there have been two examples. The first was towards President Obama after former President Clinton's Democratic Convention speech.  The second - and more dramatic - was the swing in Governor Romney's favour following the first Presidential Debate.

An alternative - more recent - origin to the one above comes from seismology. On the Richter Scale indicates the strength of an earthquake.

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