While momentum shifts have not been so noticeable in national polls for the Democratic nominee for president (nearly all of which have Hillary Clinton with a significant lead over Barack Obama), such shifts have occurred in early polling at the state level, including Iowa, which will hold the first contest for delegates in the nation in January 2008. In the latest survey by American Research Group—its fourth poll since December 2006—a surge in support for John Edwards has put him in a virtual tie with Clinton.
The last field date of the ARG survey, conducted March 19-22, overlapped one day with the news cycle in which Edwards and his (very popular) wife Elizabeth announced her cancer had returned. The press coverage following that announcement for Edwards, and his decision to continue his campaign, was exceedingly positive.
In the ARG poll, Clinton remains at the top, the preference of 34 percent of likely Democratic caucus voters. Clinton's support has remained consistent across all four surveys—hovering around one-third in all of them (31, 35, 31, and 34 percent respectively from December to March).
Edwards now polls at 33 percent, up from 27 percent in February and 18 percent in late January. The rise in support for Edwards is correlated with former Iowa Governor Tom Vilsack's decision to drop out of the race in February (Vilsack was polling in the low double digits in the Hawkeye State) as well as a tapering off in the buzz over Barack Obama. Obama's support of 16 percent in Iowa in March is down from 23 percent in February and close to his original level of support in late January before Vilsack ended his presidential bid (14 percent).
It is unclear whether or not Vilsack's reported endorsement of Clinton (likely to come on Monday) will give Clinton any boost in support, or whether Edwards will get a further bump (particularly from female voters) in light of the developments with his wife's health. Des Moines Register political columnist David Yepsen speculates the 'sympathy factor' for Mrs. Edwards will likely have significant political currency with the Edwards campaign in Iowa.