If there's any truth in the recent report alleging that President Trump instructed Michael Cohen to lie to Congress, then Trump is almost certainly guilty of obstruction of justice.
Whether this is the case remains very much an open question. The Buzzfeed report claiming that Trump instructed his former attorney to give Congress a misleading account of his business activities in Russia relies upon the testimony of anonymous sources who are supposed have access to documents related to the special counsel investigation. Since its publication there have been conflicting accounts of whether the authors of the story have actually seen the documents from which their claims are said to originate. Then there is the question of Cohen's trustworthiness. The fact that a document somewhere may quote him making this claim does not make it true. This is the line being taken by Trump's own legal counsel. “If you believe Cohen I can get you a great deal on the Brooklyn Bridge,” Rudy Giuliani said in a statement on Friday.
But let's assume that it is true and there is, as the report suggests, concrete evidence in the form of text messages and emails. Would Republicans in Congress turn on Trump? There are several reasons why this seems unlikely.
For one thing, absent any evidence of actual collusion between Trump and the Kremlin, it is difficult to imagine rank-and-file Republicans, to say nothing of the party's leadership, thinking there is anything wrong with obstructing a long-winded investigation of non-crimes. This was, after all, the line taken by Senate Democrats after Bill Clinton was impeached for lying himself. Of course Republicans will say that he should not have instructed Cohen to lie — it was a terrible blunder, something he regrets and has apologized for, a sad day for our country, bla bla bla — but they will stop short of voting to remove him from office.
The fact that a handful of Republicans — Ben Sasse and Mitt Romney, perhaps even Lindsey Graham — would probably side with Democrats during a Senate trial makes this outcome even more likely. A handful of defections would not change the math, but it would give the party sufficient cover going forward. The handful of people — they seem to exist only on the editorial pages of major newspapers and in well-remunerated positions at right-of-center think tanks — who support all the worst aspects of the president's agenda while disliking the man would be satisfied. As long as the president's would-be opponents continue to caucus with the party of which he is the head, it makes no difference. Whatever they might tell themselves and their friends, #NeverTrumper Republicans are by definition stooges for the president.
Meanwhile, Senate Majority Leader Mitch McConnell has almost nothing to lose and everything to gain by backing Trump for as long as he can. The 2018 midterm election settled for good the question of whether voters care more about GOP talking points or the Trump brand. Whether Trump wins re-election in 2020 depends upon any number of things, not least the question of whether the Democrats nominate someone who can recapture the Midwest. But without Trump the GOP is a losing party, one whose ceiling is Mitt Romney's performance in 2012. Republican leadership understands this, however dimly.
As long as winning is the most important thing to the GOP, they will not abandon their man in the White House.