The measure of a party’s commitment to limiting government is what it does in power. In opposition a party can do a few things, but obviously not as much as when it wields both executive and legislative authority.

By that criterion, what is one to make of the Republican Party?

With one house of one branch of government under its control, the GOP is fighting desperately to stop an expansion of social insurance—Obamacare—and might like to cut non-defense spending as well. Because holding the House of Representatives is not enough to repeal legislation, the GOP has to resort to more drastic steps—refusing to pass a continuing resolution to fund government if Obamacare is part of the CR. And now the party is signaling a refusal to raise the debt ceiling unless it gets something in return. Without a debt-ceiling hike, the federal government begins to default in about a week.

But no problem: shouldn’t a small-government party be happy to close the government for a while, showing everyone just which employees are “essential”? And isn’t the national debt something a small-government party wants to see capped and paid down, not constantly raised?

This would all make sense—Republicans are a small-government party, standing for principle—if not for what Republicans actually do when they are the party in power.

Obamacare is a bad law that addresses a real problem: everyone needs healthcare, insurance is a way of meeting unknown future needs, yet not everyone had insurance. By contrast, Medicare Part D, the prescription-drug add-on to Medicare passed by a Republican House and signed into law by a Republican president in 2003, was gratuitous: a new benefit for the wealthiest age cohort. But the small-government party supported it. And as is well known, Medicare Part D is but an outward and visible sign of the GOP’s overall spending tendencies the last time the party held power.

The story that voters are told today, both by Republicans themselves and by a mainstream media that views Republicans in general as extremely anti-government, is that the party has changed over the last five years. Whatever a Republican House may have done in 2003 just isn’t relevant to what a different Republican House wants in 2013.

There are two problems with that storyline. First, the 2003 Republican House was a continuation of the 1990s Republican House, which also shut down the government in a spending battle with a Democratic president. Something must have happened between 1995 and 2003 that led the Republican House to change its philosophy. In fact, several things happened, but the most important was the election of a Republican president in 2000. A Republican House would not have been eager to pass something like Medicare Part D under a Democratic president.

So if the small-government 1995 Republicans became the big-spending 2003 Republicans, what reason is there to believe that small-government 2013 Republicans won’t become big-spending 2017 or 2021 Republicans?

The second problem with the story that says Republicans have changed is that for all the new blood that has come into the congressional GOP, the party’s leaders—elected by its members, of course—are much the same people responsible for the 2003 Republican Party. John Boehner, Eric Cantor, Mitch McConnell, and Paul Ryan—the GOP’s present House and Senate leaders and its 2012 vice presidential nominee—all voted for Medicare Part D. The party’s 2012 nominee, Mitt Romney, instituted his own Obamacare-like system as governor of Massachusetts. This is a surprising leadership cadre for a party that’s supposed to be radically different in 2013 from what it was in 2003.

Instead of “Republicans have really changed,” a more plausible story is, “Republicans are pretty much the same,” both in key personnel and in principle. The principle the party has lived by in 1995, in 2003, and in 2013 is that Republican presidents and their policies are good, Democratic presidents and their policies are bad. The size of government or the national debt is a secondary concern, if that. The real test is what a party does when it holds power, not how desperately it struggles when the other party has power.

How does Ted Cruz fit into this? Although he worked for the George W. Bush Justice Department, he’s only been in the Senate while Obama has been in office, so whether his behavior would be the same under a Republican president is an open question. There were anti-spending Republicans who in 2003 voted against Bush’s entitlement expansion—Ron Paul and Jim DeMint among them—and there are others today, such as Justin Amash, who have shown an independent streak that suggests they would behave under a president from their own party as they do under one from the other party.

But the consistent faction in the 2003 GOP was not setting the party’s direction then, and today’s insurgents have yet to gain a foothold in leadership that suggests they will set the agenda in the future—however useful they may be to the party’s confrontational strategy whenever a Democrat is in office.

The GOP won’t be a serious small-government party until it attains power and has actually wielded that power to implement significant reforms and reductions. Everything that’s happening now is just theater—whatever the outcome of the present standoff, even if the House Republicans get everything they want, it could all be undone by another big-government Republican president and compliant Congress. The opposite is also true: if small-government Republicans get nothing out of this battle—if a clean CR and debt-ceiling hike pass—they would still have an opportunity to get what they want the next time they win national power, assuming they’re serious about what they want—more serious the GOP proved to be under Bush.

The question now becomes whether the shutdown and prospect of a default is increasing or decreasing the chances of Republicans gaining power nationally. About that, there’s not much doubt: these antics are hurting Republicans nationally more than Democrats. This doesn’t matter so much for retaining control of the House—Democrats won more votes for the House last year but Republicans maintained control because of the way districts are configured—but it does matter in terms of winning the White House. (What the shutdown and default mean for control of the Senate can be argued either way.)

If small-government Republicans, however many of them there are, are undercutting the chances of getting a president who could actually achieve their major goals by today fighting unpopular battles over continuing resolutions and the debt ceiling, are they really serious small-government politicians after all? At the very least, they would be short-sighted and ineffective small-government politicians; at worst, they would be mere actors, mouthing the lines and even performing small-government actions, but actions of no long-term substance.

Reducing and restructuring government is going to take time and careful planning, but what we see from the Republicans—abetted by certain activist groups and entertainers who feed off over-emotional listeners, viewers, and donors—is a party whose leadership and record in power is big government and whose committed small-government faction is crippling rather than augmenting its appeal to the country as a whole. This is a recipe for defeat of the small-government faction in future presidential nominating contests—where the Republican Party has shown a longstanding preference for candidates who seem like they can win over centrist voters—and that means even if a Republican can win the White House again in the near future, he’s more likely to be a Republican in the Bush mold.

The challenge for small-government Republicans today—the principled, consistent, and serious ones—is to win over the center of the country and a national electorate. Does the shutdown, let alone a threat of default, really help with that?