Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are his own.

(CNN) Confirming the warnings and worst fears of progressives, House Speaker Paul Ryan made it plain this week: the ultimate aim of Republican lawmakers -- and their number one priority in January -- is to shrink the Medicare program that provides health insurance to the elderly and disabled.

"Next year we're going to have to get back at entitlement reform," Ryan said on a Wisconsin radio talk show, calling Medicare the "biggest entitlement that's got to have reform."

That's code for resuming a decades-long fight against government-supported health care by conservatives, who fought bitterly against the creation of Medicare in 1965 and have been trying to cripple or kill the program ever since.

Recall that the creation of health insurance for America's poor and elderly -- something that President Harry Truman attempted, without success, in 1945, 1947 and 1949 -- was frustrated at every turn by conservatives in both political parties.

As CNN contributor Julian Zelizer has recounted , the program finally got passed following the Democratic landslide of 1964, when President Lyndon Johnson's re-election against Barry Goldwater swept commanding Democratic majorities into the House (295 seats) and Senate (68 seats).

Democrats got the long-sought program for senior health care: in 1965 Johnson signed the Medicare bill into law with Truman sitting at his side. The ex-president was enrolled as the program's first member.

But conservative opposition never wavered or waned. In the closing weeks before final passage of the Medicare bill, Ronald Reagan -- then a rising star in conservative Republican politics -- recorded a famous message calling Medicare "socialism" and urging voters to contact member of Congress and urge a "no" vote.

JUST WATCHED Cancer patients turned away from clinics Replay More Videos ... MUST WATCH Cancer patients turned away from clinics 02:18

If Medicare should pass, Reagan warned, "behind it will come other federal programs that will invade every area of freedom as we have known it in this country. And if you don't do this and if I don't do it, one of these days we are going to spend our sunset years telling our children and our children's children, what it once was like in America when men were free."

For a certain type of hard-right conservative Republican, Reagan's call remains relevant and urgent to this day. Having failed to repeal Medicare outright -- the program is wildly popular, serving more than 55 million seniors (about 15% of the US population, says AARP ) and disabled Americans -- Republicans have moved to a three-part "starve the beast" strategy.

Part one is to slash taxes and drastically lower the amount of revenue available to the federal government. The tax bill that GOP majorities recently approved in both houses of Congress accomplishes that nicely, adding $1 trillion to the federal budget deficit under the most optimistic economic scenario, according to the nonpartisan Joint Committee on Taxation.

Part two of the plan is to suddenly recoil in horror at the fact of the budget deficit (yes, the same one that Republicans happily conjured up by cutting taxes). Ryan's radio interview is a step in that direction. "Frankly, it's the health care entitlements that are the big drivers of our debt," he said -- just days after happily adding a trillion to the tab with tax cuts.

JUST WATCHED Mulvaney: Trump wants to protect entitlements Replay More Videos ... MUST WATCH Mulvaney: Trump wants to protect entitlements 01:32

Piling up debt and deficits sets the stage for the third and concluding strategy: to lower the debt by dialing back Medicare eligibility, lowering the benefits and otherwise crippling the program.

Democrats warned about this throughout the debate over the tax cut bill, which passed without a single Democratic vote in the House or Senate. They must now gear up for a showdown with Ryan and other conservatives who are poised to take a big step in the direction of ending a program that Reagan Republicans wanted to eliminate from Day One.