Rep. Steve King is trying to convince his Republican colleagues to support a bill that would fully repeal the Affordable Care Act.

King wrote to House members on Tuesday that they should try to scrap all of President Obama's healthcare law by signing on to his legislation, which he called a "magic 40-word repeal bill."

"With a Republican president, House and Senate, there is simply no excuse to fail to make good on our long-held vow to repeal this unconstitutional and egregious law," King wrote in a letter sent to House Republicans. "To accomplish this critical priority, my legislation remains the vehicle, completely repealing Obamacare from United States code."

But King didn't address the chief reason Republicans aren't trying to ditch all of the law: their lack of 60 votes in the Senate to overcome filibusters from Democrats. Instead, Republicans plan to advance a budget reconciliation bill to repeal the law, which allows them to avoid a Democratic filibuster, although it only allows legislation that contains provisions that affect federal spending.

King, one of the most conservative House members, isn't the only advocate for attempting full Obamacare repeal. The Heritage Foundation has also been pushing congressional leadership to repeal all of the healthcare law in the reconciliation bill, even though that's unlikely to pass muster under the Senate parliamentarian.