There’s a good political argument to be made against Republicans trying to use the threat of a federal government shutdown to win support for their goal of defunding ObamaCare. James Antle explained in a column this week for The Daily Caller why many conservatives are unlikely to buy that argument.

A funny thing happened to the Republican Party on the way to the next election.

Conservatives have started expecting Republicans to actually do the conservative things they say they are going to do. When even the suspicion exists that a Republican politician is going to let them down, conservatives make their lives a living hell. …

… Everyone from the mainstream media to the Republican establishment hates this. They think it is reckless. But there is a dirty little secret that provides some necessary context: Republicans frequently don’t keep their promises to conservatives.

Remember former New Hampshire Sen. Bob Smith? A great lumbering bear of a man, he was a conservative who reached this unhappy conclusion a decade before the tea party existed. He left the Republican Party to become an independent, but not before reading the party platform aloud from the Senate floor to point out how little of it the GOP Congress had actually tried to enact.

There was no effort to abolish the Departments of Energy, Education, Commerce or Housing and Urban Development, Smith observed. No attempt to defund the Legal Services Corporation or the National Endowment for the Arts.

Think of those last two budget items in the context of today’s Obamacare defunding debate. The NEA and Legal Services Corporation are two tiny expenditures. Between the two of them, they don’t cost Uncle Sam $1 billion a year. Among their direct beneficiaries are lawyers and people who soak crucifixes in jars of urine, not uninsured kids with cancer.

If you can’t defund the Legal Services Corporation or NEA, how can you hope to defund Obamacare? …

… The only leverage Republicans have to make Obama sign a continuing resolution that strips funding from his biggest policy achievement is a government shutdown polls indicate most Americans — and perhaps most Republicans — don’t want and would blame Republicans for instigating. …

… If Republicans had any credibility, they could explain to their conservative base that this strategy is unlikely to work and may prevent them from being able to roll back Obamacare in the future.

But they don’t have any credibility, because many conservatives believe — for good reason — that Washington Republicans don’t really care about getting rid of Obamacare. Or doing anything else besides getting re-elected, for that matter.