Democratic congressman Alan Grayson beat the Republicans at their own game last week, when he ripped into them for dragging their feet on the American healthcare crisis. On the floor of the House of Representatives, he summarised the Republican healthcare plan as: "Don't get sick, and if you do get sick, die quickly." It has caught Republicans like a deer in the headlights, understandably so because Republicans are not used to Democrats with guts.

Far from surrendering to immediate Republican outrage and demands for apology, Grayson stood firmly by his stance, teasing his opponents that he'll apologise, but "to the dead and their families" for government's failure to improve the system. In fact, Grayson has since stepped up his rhetoric in a recent media blitz, calling Republicans "knuckle-dragging Neanderthals" and "a lie factory" whose only approach to policy is obstructionism. By failing to produce a counter-proposal in the following days, Republicans have effectively proven Grayson's point.

This kind of pugnacious spirit is common among Republicans but very rare among Democrats, which is largely why Democrats so often get trampled in legislative battles where they have the upper-hand politically, intellectually, morally, historically and in opinion polls. Grayson's star power has surged since his remarks. While the GOP has designated him public enemy number one, Grayson has lit up the Democratic base.

What's unique about Grayson is that he's passionate about championing liberal causes, and he forcefully calls out the lies of his Republican opponents and the vapidity of today's conservative movement. With the significant rightward shift of the Democratic party in the last few decades, progressives are hardly represented in American government any longer. Though there are a few notable exceptions, none have quite the determination Grayson showed this week.

In the last 30 years, Republicans have yanked America further to the right than was once conceivable. Democrats have been complicit in this. Many Democrats sat idly by – if not supported – Republicans starting unnecessary and destructive wars, violating the Constitution and international law, redistributing wealth upward from the working poor to the rich, letting tens of millions lose their health care, and actively ignoring the threat of global climate change.

Democrats have effectively allowed Republicans to elide the word "liberal" from an adjective into a smear. This continues today, despite the fact that conservatives have steered America to one of its darkest places yet. President Obama's self-consciously conciliatory approach plays right into this meme. The zeal with which Republicans continue to promote their agenda, despite its immense failures, provides a stark contrast to the tepid Democratic spirit.

This is why Grayson is not a typical Democrat, and why he's exactly what Democrats have needed for a long time. The party dominates the House of Representatives, has a filibuster-proof majority in the Senate, and boasts a popular president – yet continues to get pushed around the bullied by the GOP, which is less popular than ever and has no serious proposals for solving today's problems. What gives? A lack of fortitude.

Capping an era of great political cynicism and unprecedented domination of money in politics, progressives have lost their footing and have tumbled behind conservatives, facing an increasingly steeper mountain to climb as Democrats continue to capitulate to the perpetrators of these quandaries. In an age where campaign contributions from wealthy, narrow interest groups are so critical to political survival, the incentive for ordinary Democrats is to play the game, not change it.

With the Democratic party slowly morphing into a watered-down Republican party, progressives have grown increasingly cynical of politics. Many feel little incentive to vote or participate in the political process. A Grayson-like fervor for liberal causes can help recapture this waning enthusiasm, perhaps eventually motivating Democrats to be real progressives again.

The internet age provides as much potential for political self-harm as it does opportunity, but Grayson seems happy to take the heat. Democrats need representatives who genuinely believe in liberal values, who have the courage to fight for their beliefs, and who won't prioritise political expediency over doing their job the right way. "We need Democrats with guts," Grayson said of the whole matter. He's right.