Sixteen Democratic senators who voted for the Affordable Care Act are asking that one of its fundraising mechanisms, a 2.3 percent tax on medical devices scheduled to take effect January 1, be delayed. Echoing arguments made by Republicans against Obamacare, the Democratic senators say the levy will cost jobs — in a statement Monday, Sen. Al Franken called it a “job-killing tax” — and also impair American competitiveness in the medical device field.

The senators, who made the request in a letter to Senate Majority Leader Harry Reid, are Franken, Richard Durbin, Charles Schumer, Patty Murray, John Kerry, Kirsten Gillibrand, Amy Klobuchar, Joseph Lieberman, Ben Nelson, Robert Casey, Debbie Stabenow, Barbara Mikulski, Kay Hagan, Herb Kohl, Jeanne Shaheen, and Richard Blumenthal. All voted for Obamacare.

Two other Democrats, senators-elect Joe Donnelly and Elizabeth Warren, also signed the letter. Donnelly voted for Obamacare as a member of the House. Warren was not in Congress at the time.

“The medical technology industry directly employs over 400,000 people in the United States and is responsible for a total of two million skilled manufacturing jobs,” the senators wrote in a December 4 letter to Reid. “We must do all we can to ensure that our country maintains its global leadership position in the medical technology industry and keeps good jobs here at home.”

Beyond that, the senators say, the medical device industry “has received little guidance about how to comply with the tax” — a reference to the apparently confused and halting nature of the Obama administration’s implementation of Obamacare.

Several of the senators, many of whom have medical device manufacturers in their states, have opposed the tax for a long time. During the Obamacare debate, for example, Franken and Klobuchar were among a group of senators who successfully pushed to reduce the tax. (The device giant Medtronic is headquartered in Minnesota.)

On Monday, Franken again expressed his opposition to the tax he voted for. “I want to repeal the medical device tax altogether,” the senator and former comedian said in a statement. “But I am concerned that we are running out of time before this job-killing tax goes into effect. So, for now, the best thing to do to ensure that this important industry continues to create jobs and producing life-saving devices is to delay this unwise tax.” Franken and other want Reid to include a provision to delay the tax in the ongoing fiscal cliff negotiations.

None of the senators found his or her earlier objections to the tax a sufficient reason to vote against Obamacare. In December 2009, with 60 votes in the Senate and a determined Republican opposition, Democrats needed every vote they could get to pass the president’s national health care plan. But now, with Obamacare — and the taxes to fund it — about to become a reality, some of those Democrats are singing a different tune.