It’s been nearly two years since President Biden signed the Inflation Reduction Act into law.

With a mix of tax incentives, federal subsidies and policy tweaks, the I.R.A. was designed to turbocharge America’s clean energy economy and put the country on the trajectory to a lower emissions future.

The Biden administration initially expected the law to provide some $370 billion in spending and tax credits for clean energy projects, but other groups expect the figure to be far higher as more companies and households take advantage of the law’s tax credits. The Brookings Institution estimated the I.R.A. could be worth $780 billion through 2031, while Goldman Sachs set a potential total cost of $1.2 trillion.

The law was also set up to be a political win for Biden, delivering jobs and setting the stage for future emissions reductions in the run-up to the president’s rematch with Donald Trump.

We’ll be checking in on the I.R.A. regularly in the coming months, but with Election Day drawing closer, this much is becoming clear: The law is delivering on the economic front, but it has not become a winning political issue.

While big, industry-changing investments are already happening, public perception of the I.R.A. is being shaped by the plodding pace of industrial development and permitting, the fuzzy math of tax incentives and a heavy dose of partisan politics.

The boom in clean energy projects is astounding. Since the passage of the I.R.A. in 2022, incentives provided by the law helped drive roughly $332 billion in new investments in clean energy and transportation technologies. Almost all of that was private investments, as opposed to government spending, spurred on by an estimated $48 billion in federal tax credits.