Yet Trump’s fixation on these issues — born of a desire to settle personal grievances and to run, for a second time, against a candidate freighted by scandal — meant his allies on Capitol Hill were compelled to devote a disproportionate share of their limited pre-election bandwidth to pursuing them. And it caused incalculable damage to the delicate relationship between Capitol Hill and the intelligence community, Republicans and Democrats alike have warned…

The narratives were often convoluted even for intense followers of the Russia investigation and Rudy Giuliani’s efforts to gather dirt on the Bidens in Ukraine. The storylines appealed almost exclusively to Trump’s diehard political base, and were featured on right-wing websites and the Fox News primetime lineup — a large audience indeed, but a narrow sliver of the wider electorate.

The investigative efforts didn’t just fail to sway voters; they turned public trust in traditionally nonpartisan arms of the federal bureaucracy into yet another partisan litmus test, lawmakers said. By twisting the arms of officials within the intelligence community and the Justice Department, Trump and his allies have politicized these institutions in a way that will leave lasting damage, Democrats say.