President Biden’s economic policies have helped spur billions of dollars in new investments in Arizona and Georgia, two crucial battleground states in the 2024 election. Yet so far, Mr. Biden’s policies appear to have done little to lift his support in either region.

Arizona and Georgia have been major beneficiaries of the Biden administration’s key policy initiatives — the Inflation Reduction Act, the CHIPS and Science Act and the bipartisan infrastructure law.

Arizona has become one of the top states for new semiconductor investments, which have totaled more than $100 billion since the CHIPS Act was introduced, according to the Semiconductor Industry Association. Georgia has been a big beneficiary of Mr. Biden’s clean energy and infrastructure laws. The state received $40 billion in private sector commitments and $10.8 billion in public investments in infrastructure, clean energy and manufacturing under Mr. Biden, according to White House data as of last month.

Still, former President Donald J. Trump has maintained a significant lead over Mr. Biden in both states, according to new polls by The New York Times and Siena College.

That dynamic illustrates one of Mr. Biden’s central challenges ahead of the presidential election. While his administration is spending huge sums of money to try and bolster American manufacturing across the country, those investments have yet to measurably show up in political support.

In part, economists say, that is because the policies that Mr. Biden has championed affect a relatively small share of a state’s work force.