Washington CNN  — 

Wisconsin Gov. Scott Walker reiterated on Monday he would sign a state law that would outlaw abortions after 20 weeks, including pregnancies that result from rape or incest.

The all-but-certain presidential candidate told reporters in his home state he would sign the bill currently working its way through Wisconsin’s Republican-controlled legislature. In March, in an open letter to the women’s group Susan B. Anthony List, Walker had said he would approve the legislation if it reached his desk.

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The bill does not include an exemption for women who become pregnant after rape or incest, but the Wisconsin governor emphasized Monday that the five-month ban was “rational and reasonable.”

“Whether you’re pro-life or not, that’s a good time to say that shouldn’t be legal after a time when an unborn child can literally feel pain,” Walker told reporters.

Walker – who forged built his political reputation on fiscal responsibility and combating unions – has in the past tried to gloss over controversial social issue debates as he fought to stay in office in his blue state.

Walker is expected to launch his presidential campaign when the legislative session in Madison concludes this month. He will join an ever-growing field of Republican presidential contenders, all of whom have endorsed a similar abortion ban on the federal level.

The House of Representatives last month passed the bill, which also does include exceptions for rape or incest.

Walker is leading the field in conservative Iowa, per a recent Des Moines Register/Bloomberg Politics poll.