The leader of the Senate Pro-Life Caucus is asking President Trump to refuse any attempts to undermine or strip pro-life measures from future spending bills.

"As you work with Congress on a deal to set discretionary spending caps for the next two fiscal years, we wish to express our support for your efforts to secure a commitment from Democratic Leaders to reject anti-life poison pill riders in the House-passed appropriations bills," states a letter currently being circulated by Sen. Steve Daines (R-Mont.), for signatures by fellow members.

Sen. Daines chairs the Senate Pro-Life Caucus, formed this year. He circulated the letter amidst negotiations between the White House and Democratic leaders on setting discretionary spending caps and the debt ceiling, Roll Call reported. Daines is insisting that any deal must not include pro-abortion riders.

Some of the pro-life protections mentioned in Daines' letter include the long-standing Hyde Amendment, a bipartisan policy that bars federal Medicaid funding of elective abortions except in cases of rape, incest, or where the life of the mother is at stake. The amendment has passed Congress every year as part of spending legislation since 1976; the rape and incest exceptions for abortion funding were added in 1994.

In June, several Democrats led by Rep. Ayanna Pressley (D-Mass.) attempted to include an amendment reversing Hyde in an appropriations package, but the amendment was pulled amidst concerns that it would affect final passage of the legislation through the Senate.

Other "poison pill riders" that Sen. Daines' letter warns Trump against include attempts to undo pro-life policies such as the Dornan Amendment that prohibits the District of Columbia from using local funds for elective abortions, as well as any reversal of the Trump administration's "Title X Protect Life Rule" and its "Protecting Life in Global Health Assistance" policy, an expansion of the Mexico Policy.

The Mexico City Policy was implemented by Presidents Ronald Reagan, George H.W. Bush, and George W. Bush and barred funding of abortions in $600 million of U.S. foreign aid. Trump's expansion applied the abortion funding ban to over $8.8 billion in U.S. foreign aid for global health assistance.

The "Title X Protect Life Rule" instituted pro-life protections into federal Title X family planning grant policy; grant recipients could not refer for abortions, nor could they "co-locate" with abortion clinics.

In January of 2019, President Trump wrote House Speaker Nancy Pelosi (D-Calif.), promising to "veto any legislation that weakens current pro-life Federal policies and laws, or that encourages the destruction of innocent human life at any stage."

Sen. Daines pressed President Trump to honor that commitment in spending caps negotiations, and pledged to fight against any pro-abortion riders in legislation.

"As members of the pro-life majority in the United States Senate, we will strongly oppose each of these anti-life poison pill riders and will work to ensure they are not inserted into any appropriations bill before the Senate, either in committee or on the floor," the letter stated.