Republican weakness cannot be simply explained by their lack of power. During the first two years of the Obama administration, Democrats had massive majorities in both chambers and Republicans fought Obama tooth and nail. Biden, on the other hand, came into office with narrow majorities and Republicans are rolling over for him. So why are Republicans acquiescing? And why aren’t they facing much outside pressure for their feebleness?
One big factor is that Trump’s takeover of the Republican Party transformed it away from one that at least claimed to care about addressing the nation’s long-term fiscal challenges. Today, conservatives are much more fired up about various cultural-war issues than they are about the fight to limit government. In some cases, they simply deprioritize concerns about the debt. In other cases, they actively oppose the idea of making a cause of fighting for less government. This is either because they see restraint as a barrier to fighting battles such as that against Big Tech censorship, or because their economic populism leads them to support entitlements and social-welfare spending.
The Tea Party was far from perfect, and its poor strategic decisions (such as the ill-fated effort to defund Obama’s signature legislative accomplishment while controlling just one chamber of Congress) have been well documented. That said, the Tea Party served one important purpose.