(CNN) - Republican South Carolina Sen. Jim DeMint turned his focus on 2012 by targeting incumbent Democratic senators over their vote on an earmark moratorium.
DeMint, a Tea Party movement favorite, sent an email to supporters of his Senate Conservatives Fund Wednesday that criticized four senators who are up for reelection 2012, noting that each member hails from a state President Obama lost in 2008.
He highlighted Montana Sen. Jon Tester, Nebraska Sen. Ben Nelson, North Dakota Sen. Kent Conrad and West Virginia Sen. Joe Manchin.
"These senators are nice folks but they have ignored the will of the American people and they must be replaced with principled conservatives in 2012," DeMint wrote. "We've already begun the process of building campaigns against these other liberals in the Senate who are driving our nation deeper and deeper into debt."
A bill to end the use of earmarks, a legislative provision that directs funds to a specific project, failed Tuesday in the Senate with a vote of 39 to 56.
To encourage Republican candidates in the next election DeMint urged his supporters to take three steps: raise money, suggest possible conservative challengers and recruit more Americans to his cause.
He said Republicans can win the four Senate races if the group raises $4 million.
DeMint supported conservative Republican and Tea Party-backed candidates throughout the 2010 campaign, and Wednesday's email marks his entry into the 2012 cycle.