Brit Hume on Fox News pointed out what he called the “Enthusiasm gap” in the Republican camp.
It is always a bad sign when you see that none of the candidates have the electricity to drive support. In 2000 and 2004 Republicans were fairly firmly Bush and reasonable united. Thus they had the Enthusiasm.
Since I think 2005 with the pasting being taken over Iraq, constant concern about illegals and scandals in various sections of the Republican parts of the government, the gap began. It widened in 2006 which led to the Democratic return to control of the Senate and House. It seems no matter who survives the nomination season it will be a tough row to hoe.