TPM: In case you don't see what this is all about

Given the amount of attention we've given to the US Attorney Purge, there's been no end of right-wing nutjobs who've written in asking just what the big deal is. In most cases, these are just attacks dressed up as questions. And I do my best -- not always successfully -- to ignore them. But interspersed in that mess of emails are a few who seem to be asking, genuinely, what the big deal is. Perhaps they're critics of the president or conservatives who genuinely don't see it. So here's how I'd answer that question.

For all the intensity and hostility awash in our politics, there are some lines we just assume aren't going to be crossed, lines that are so basic that the civil compact itself can't easily survive if they're not respected.

One of those is the vote. Whoever's in power and however intense things get, most of us assume that the party in power won't interfere with the vote count. We also assume that the administration won't use the IRS to harrass or imprison political opponents. And we assume that criminal prosecutions will be undertaken or not undertaken on the facts.

Yes, there's prosecutorial discretion. And the grandstanding, press-hungry DA is almost a cliche. But when a politician gets indicted for corruption we basically all assume it's because they're corrupt -- or, given the assumption of innocence, that the prosecution is undertaken because the prosecutor believes their case is strong and that the defendent committed the crime.

Now, again, life is made of grey areas. And our laws and regulations often take into account that even people of good faith may not be able to impartially investigate their own. That's why we had the Independent Counsel statute. The partisan affiliation of prosecutors and judges often hangs in the background of cases. And probably most Democrats and Republicans feel a bit better when a member of their party is brought down by a prosecutor of the same party because then you can assume -- whatever fairness or unfairness may have been involved -- that partisanship wasn't a factor.

So, all of this is to say that no system is perfect and partisan affiliation may distort the justice system at the margins.

But none of what we're seeing here is at the margins. What we seem to see are repeated cases in which US Attorneys were fired for not pursuing bogus prosecutions of persons of the opposite party. Or vice versa. There's little doubt that that is why McKay and Iglesias were fired and there's mounting evidence that this was the case in other firings as well. The idea that a senator calls a US Attorney at home just weeks before a federal elections and tries to jawbone him into indicting someone to help a friend get reelected is shocking. Think about it for a second. It's genuinely shocking. At a minimum one would imagine such bad acts take place with more indirection and deniability. And yet the Domenici-Iglesias call has now been relegated to the status of a footnote in the expanding scandal, notwithstanding the fact that there's now documentary evidence showing that Domenici's substantial calls to the White House and Justice Department played a direct role in getting Iglesias fired.

So what you have here is this basic line being breached. But not only that. What is equally threatening is the systematic nature of the offense. This isn't one US Attorney out to get Democrats or one rogue senator trying to monkey around with the justice system. The same thing happened in Washington state and New Mexico -- with the same sort of complaints being received and acted upon at the White House and the Department of Justice. Indeed, there appears to have been a whole process in place to root out prosecutors who wouldn't prostitute their offices for partisan goals.

We all understand that politics and the law aren't two hermetically sealed domains. And we understand that partisanship may come into play at the margins. But we expect it to be the exception to the rule and a rare one. But here it appears to have become the rule rather than the exception, a systematic effort at the highest levels to hijack the Justice Department and use it to advance the interest of one party over the other by use of selective prosecution.

-- Josh Marshall