Allen tried to connect Collins to George W. Bush, but these tactics failed as Collins maintained her image as a very popular, moderate, independent Republican. She obtained an endorsement from Independent and former Democratic U.S. Senator Joe Lieberman.
CQ Politics rated this race as 'Leans Republican'.The Cook Political Report considered it 'Lean Republican'.The Rothenberg Political Report considered it a 'Clear Advantage for Incumbent Party'.UpFront Politics listed the race as 'Leans Republican'. Swing State Project listed the race as "Likely Republican." The Hotline's Senate Rankings showed the Maine Senate race fall from 7th- to 11th-most competitive senate race in the country.