No matter who President Trump nominated to fill the vacant Supreme Court seat on Monday, their confirmation process would have played out in a Senate under the control of a slim Republican majority and at the tail end of a midterm election season in which several Democratic incumbents are up for re-election in red states.

That means Trump's nominee, Judge Brett Kavanaugh, could plausibly lose the support of some Republicans — the likely defectors being Susan Collins of Maine and Lisa Murkowski of Alaska — and still be confirmed.

[ WATCH: Supreme Court nominee Brett Kavanaugh answers Chuck Schumer on Roe v. Wade at his 2006 confirmation hearing]

Three vulnerable Democratic incumbents voted to confirm Justice Neil Gorsuch last year, long before their contentious re-election battles even started: Joe Manchin of West Virginia, Joe Donnelly of Indiana, and Heidi Heitkamp of North Dakota. Their votes are not guaranteed, but it's worth remembering those Democrats, each of whom is fighting for their lives in a state where Trump's approval rating is relatively high, voted for Gorsuch under even less political pressure a year ago. That makes at least three likely yea votes from the opposing party. Trump could also potentially pick up the support of Democratic incumbents like Claire McCaskill of Missouri or Jon Tester of Montana, but that seems unlikely given their records.

On the other hand, if Trump spent adequate time conferring with Collins and Murkowski in particular before landing on his nominee, and wanted that person to be confirmed with total Republican support, the confirmation process could play out under less dramatic stakes. Collins and Murkowski could at least signal their support early on, and Democrats would be left powerless to stop the confirmation.

In that scenario, Democrats would focus their time negotiating a strategy for the party's most vulnerable incumbents, contemplating whether it's better for someone with McCaskill's re-election prospects to side with Trump, given that his nominee is certain to be confirmed regardless of how she votes.

Given the strong likelihood that Trump will keep his three Democratic Gorsuch votes this time around, and that Collins and Murkowski will face intense pressure to oppose the nominee no matter who it is, the White House is probably not banking fully on receiving total Republican support.

That doesn't mean the administration won't get it. But those three Democratic Gorsuch votes may well have liberated Trump to nominate the candidate he was most comfortable with personally, even if that candidate would struggle to win every GOP vote in the upper chamber.