
U.S. Senators John Kerry (left),John McCain (centre),Joe Liebermann (right) at 2011 State of the Union Address. Wikicommons/ Whitehouse photogallery. Some rights reserved.
It’s more than doors between government and the businesses that they supposedly regulate that go round and round. One of the other swinging doors is between the Democratic and Republican Parties.
A second door
Perhaps the best known case is when Al Gore ran for president in 2000, he picked Joe Lieberman as his running mate. Then, in 2008, Lieberman showed up at the Republican national convention to endorse John McCain for president. Between those two campaigns, John Kerry, the 2004 Democratic presidential nominee, was rumored to be leaning towards ask Republican John McCain to be his running mate.