Republican lawmakers in Iowa have launched an effort to impeach four state supreme court justices over their decision to strike down a ban on gay marriage in the state last year. 

The new effort comes just as the 2012 GOP presidential primary heats up and the two are sure to intersect. Iowa conservatives, led by former gubernatorial contender Bob Vander Plaats, will likely pressure GOP hopefuls to weigh in. 

Just last month, Vander Plaats led a successful effort to oust three other justices over the gay marriage issue in retention elections. Several 2012 GOP hopefuls voiced support for that effort. 

Now, the same core of lawmakers and activists are targeting the remaining four judges. 

Vander Plaats, who chaired former Arkansas Gov. Mike Huckabee's winning Iowa effort in 2008, recently formed a new social conservative organization with the goal of promoting conservative causes and playing a major role in the 2012 caucuses. He recently told The Ballot Box that his group will endorse before the caucus. 

"Our base of support largely consists of pro-family conservatives and we want to make sure we see these candidates up close and hear them first-hand," he said.

According to the AP, it would take just a majority vote in the Republican-led state legislature to approve impeachment, but a two-thirds vote in the state Senate, which is controlled by Democrats.