If an infrastructure bill had been passed it may have helped, but Im not convinced it would have prevented what happened last week.
It is a shame though that Ryan and McConnell pursued the doomed effort to repeal Obamacare and the tax cuts first.
The tax cuts were mostly good, as all tax payers got a cut, and the corporate rate got a needed reduction to be more competitive with rates in other western nations. In hindsight Trump should have insisted that the carried interest matter that Ryan and his cronies removed be included in the bill. Most of the guys benefiting from it are probably Democrats so screw em anyway. It would have helped deflect the tax cuts for the rich charge.
On Obamacare the GOP of course faced a biased press that lied about their replacement plan, but at the same time I think many Republicans were stuck in the midterm election mindset from the Obama years, where they gained lots of seats because of the unpopularity and negative effects of the aca. The simple fact is that by 2017 public opinion towards Obamacare had shifted due mostly to the pre-existing clauses that are overwhelmingly popular. Again, the Left lied about the GOP removing protections for pre-existing conditions but the GOP response was, as usual, weak and unfocused. And knowing how popular those provisions were any replacement plan should have been ironclad in protect them.
Trump also championed Social Security in his 2016 campaign.
But this year he cut the tax that pays for Social Security - the FICA tax (so-called payroll tax). Although its a temporary cut, it allowed Biden to tell seniors that Trump was threatening Social Security. It was a tactical error, and Trumps share of seniors in the middle west did go down from 2016 accord to exit polls
Bottom line: Trump won as a populist, not a Romney/Ryan tax cutter. But he let Ryan and Mitch blunt a lot of his populism