The American left has often been quick to dismiss the incoming class of conservative legislators as half-baked lunatics. But lost in that unbridled contempt is any acknowledgment of the potential of a certain Republican senator-elect from Kentucky to act as a sorely-needed boon to progressive causes. You'd hardly know it from all the handwringing, but Rand Paul – much maligned as the Tea Party's crazed kingpin – has actually opposed both the Iraq war and the Patriot Act with admirable consistency, denounced corporate welfare, questioned the premise of federal drug policy, called for meaningful cuts to defense spending, chastised his own party for supporting torture, and generally advocated a platform that is structured to impede the unwarranted exertion of government power. Once upon a time, that was the kind of thing progressives stood for.

Those on the left who reflexively conflate the Paul brand of libertarianism – embodied most robustly by his father Ron – with the aims of cynical theocrats like Sarah Palin or Jim DeMint not only abdicate any pretence of intellectual responsibility; they deprive themselves of a powerful ally. There's a reason why Mitch McConnell and the rest of the Republican establishment were spooked by the idea of Rand Paul in a GOP senate primary. He'll be a thorn in their sides for years to come and, along the way, likely foster a few schisms within an otherwise absurdly uniform caucus. This must be a positive development.

An anti-war Republican holding his party accountable and shaking things up in an institution mostly known for its insufferable stagnation? I fail to see the problem, especially when the alternative was the loathsome Blue Dog Jack Conway, who ran an ad suggesting Paul was not qualified for office on the grounds that he failed to demonstrate a sufficiently fervent worship of Christ.

It is, of course, doubtful that Rand Paul would ever sign on for a progressive economic proposal, but that's certainly no surprise from a statewide officeholder in Kentucky. And does anyone seriously think Jack Conway would've taken up cause with Bernie Sanders? In Paul, at least we could have on our hands a genuine maverick who is not beholden to any apparent partisan interest. And if the Senate needs anything right now, it's less inane procedural manoeuvring and a few new ideas. I agree with Robert Scheer, who argues that Rand Paul will extend the political conversation beyond the arbitrarily delineated ideological spectrum in which our discourse is currently held captive. His presence could challenge the stale orthodoxy of both parties, and as he has described on the Rachel Maddow show, forge a coalition between civil libertarian-minded senators irrespective of prior allegiance.

If Rand is even half as audacious and principled as Ron, there is ample cause for optimism. The left must acknowledge that on multiple occasions, and on issues of profound importance, Ron Paul has been no less than heroic. From his dissection of Rudy Giuliani's smug apologetic for US foreign policy before a hostile Republican primary audience, to last week's impassioned defense of WikiLeaks on the floor of the House, Paul the elder has done far more to advance and defend what I could consider progressive causes than your average milquetoast Democrat. That he regularly sponsors legislation with stalwarts of the left like Dennis Kucinich and Alan Grayson should be persuasive enough for sceptics.

I wouldn't suggest that Rand Paul is sure to mimic the views of his father upon entering office – though they will, reportedly, be sharing accommodation. It's true that he made certain rhetorical concessions in the campaign, although I'd argue the necessity to do so was simply a reality of running for high office in Kentucky. Legitimate reservations aside, it's hard to deny that Rand Paul agitating in those stuffy chambers will be on the whole a welcome change.

And anything – anything – is better than Jim Bunning.