First in terms of the economy: If Reagan pushes for a supply-side type of stimulus, he'll probably get it passed. At that time, most Republicans were Bob Dole/Pete Domenici-esque in that they favored balanced budgets over tax cuts. Democrats were more prone to supporting big cuts, even folks like Ted Kennedy. So he can get that passed, but won't get the spending cuts to balance the budget. In fact, you probably have a much greater deficit.
On other domestic issues, Reagan is consistently blocked by Congress. Imagine Carter's predicament, but worse. The only advantage is that it's not partisan infighting, and is more just an ideological struggle.
On foreign policy, he's probably worse off than Carter only because detente will totally break down and much faster. In terms of Iran, maybe intervention can lead to a military regime, but that's not a whole lot better long term than the Ayatollah.
On other domestic issues, Reagan is consistently blocked by Congress. Imagine Carter's predicament, but worse. The only advantage is that it's not partisan infighting, and is more just an ideological struggle.
On foreign policy, he's probably worse off than Carter only because detente will totally break down and much faster. In terms of Iran, maybe intervention can lead to a military regime, but that's not a whole lot better long term than the Ayatollah.