The scale is dramatically different: While the Obama administration dumped $535 million alone into Solyndra — the California solar panel company that subsequently filed for bankruptcy protection — the energy loans, grants and other financial help Romney distributed during four years as governor add up to just a fraction of that amount.

But Democrats — and even some Republicans — say the core issue is the same: If the federal government shouldn’t be betting on one company rather than the other, then neither should the state of Massachusetts…

Massachusetts did bank millions when it sold shares of Evergreen Solar stock offered as part of its payback for the initial loan. But that early investment was followed by tens of millions more from Romney’s successor, Democratic Gov. Deval Patrick, and it all ended up backfiring when the company filed last year for Chapter 11.

Some of the companies that landed coveted spots in the Massachusetts Green Energy Fund also have stumbled.