After attacking conservative groups for their efforts to prevent the funding of Obamacare, Mr. McConnell, who is facing a primary challenge in his 2014 re-election race, is now seeking to portray himself as a conservative darling, championing fiscal austerity by voicing opposition to the budget proposal. (My organization has not endorsed a candidate in that race.) Doing so gives him some nifty talking points that align with most conservative groups, but it is little more than parliamentary sleight of hand.

Consider how he handled the vote on the bill. To defeat a filibuster, its supporters needed 60 senators to win cloture and move to a final vote. Instead of rallying his troops against the vote, Mr. McConnell allowed a handful of Republicans in battleground states — who needed to be seen as supporting the bill — to vote for cloture, while he and the rest railed against it, casting themselves in the role of budget hawks.

With cloture accomplished, a dozen Republicans were then free to vote against final passage if they need wiggle room when they’re confronted on the campaign trail next fall by voters demanding action on government spending. Mr. McConnell and many Senate Republicans used the vote to manipulate the system, allowing them to cast themselves as deal makers or principled conservatives, depending on their audience.

This is not principled policy making; what we’re seeing is simple gamesmanship that raises legitimate questions about which values Republicans truly hold and which are merely interchangeable with those of Democrats.

The job of Tea Party groups and other conservatives is pretty simple: to inform Americans about the need for restraint in spending, tax relief, pro-growth economic policies and individual liberty — and to support the men and women who pledge to promote these positions. To the extent that the speaker of the House and Senate Republicans are attacking such groups, it looks as if we’re doing our job.

But after this budget vote, our job expands to include informing Americans about who keeps their word in Congress and who does not.

When establishment Republicans call spending increases spending cuts, deny that raising taxes is a hike, and champion deficit reduction that doesn’t scratch the surface of our nation’s debt, it suggests a detachment from the facts. But when those who voted for them criticize their elected officials for not keeping their promises, and are then attacked for doing so, it suggests that Kurt Vonnegut was right in observing, “A sane person to an insane society must appear insane.”