One of Sen. Max BaucusMax Sieben BaucusOvernight Defense: McCain honored in Capitol ceremony | Mattis extends border deployment | Trump to embark on four-country trip after midterms Congress gives McCain the highest honor Judge boots Green Party from Montana ballot in boost to Tester MORE's (D-Mont.) own constituents stars in a new ad pressuring the senator on healthcare reform legislation.

The Progressive Change Campaign Committee and Democracy for America, two liberal groups, launched a new ad airing this week in Montana and Washington, seeking to pressure the Senate Finance Committee chairman into backing a public (or "government-run") option in healthcare reform.

The ad features a Montana father who racked up six figures of debt due to heart surgery he had to have while he was uninsured.

"None of this debt would have piled up if I’d had the option of buying into a public health insurance plan," says the father, Bing Perrine, in the ad.

Baucus has drawn the ire of liberal Democrats over his decision to eschew including a public option in his committee's health reform bill in favor of nonprofit cooperatives, in an effort to charm the votes of Republicans and centrist Democrats.

The ad will begin airing Tuesday, when the Finance Committee will vote on amendments to include a public option in the Baucus bill.