Image Credit: Chris Carlson/AP Photo

Some Republican presidential candidates today turned their attacks on Rick Santorum's congressional voting record, hoping to portray the former Pennsylvania senator as a classic Washington insider as he picks up a head of steam in Iowa caucus polling.

"If you look at the spending issue, Sen. Santorum voted for the bridge to nowhere," Rep. Michele Bachmann, R-Minn., said on "Fox News Sunday." "Santorum has stood for earmarks, stood for spending."

Tea Party conservatives and President Obama have long characterized the process of "earmarking" as a wasteful and sometimes corrupt. Lawmakers have used the earmarking process to divert money to moneyed interest at the local level but some, such as Senate Majority Leader Harry Reid, D-Nev., still defend the practice as a way to encourage cooperation in a divided Congress.

Santorum, a self-proclaimed fiscal conservative, defended his decision to divert money to Pennsylvania today while on "Meet the Press."

"I don't regret going out at the time and making sure that the people of Pennsylvania, who I was elected to represent, got resources back into the state after spending money," Santorum said.

But multiple GOP contenders renewed attacks today on his voting record, a bet that spending earmarked for Pennsylvania would not play well in the Iowa presidential primary.

"Why was it important to vote for a Montana Sheep Institute?" Gov. Rick Perry said on "Fox News Sunday," referring to another Santorum vote.

But many politicians, including Perry, have benefited from earmarks when accepting money from Washington through the appropriations process in the Congress. Perry has accepted such projects as governor of Texas but today attributed his decision to accept money to a system controlled by Washington.

"That is the process that they put in place in Washington, D.C. And I will tell you that the reason that states have to go up there and play that game is because Washington is broken," he said.

Santorum, while defending his choice to appropriate money back to Pennsylvania, does regret some votes. "I've made some mistakes," Santorum said on CNN earlier this week.

"For example, you know, I talk all the time about having voted for No Child Left Behind. And, you know, it was a mistake. You know, it was a … a dumb thing to vote for because it gave more federal control over education, which was something that, you know, I didn't advocate for, but I voted for."

Also at issue is his 2003 vote to extend Medicare drug benefits to seniors, a vote that some fiscal conservatives have come to characterize as irresponsible.  Santorum admitted to making a mistake on Medicare during a 2011 "Fox News Sunday" appearance.