As investigators continue to close in on Donald Trump's ties to Russia, and as his business conflicts continue to render his presidency illegitimate, a groundswell of support for his impeachment is growing among the resistance, and beyond. Before lawmakers can take that step, however, an independent commission and/or special prosecutor must be appointed in order to shine a light on the evidence needed to make impeachment stick.

Donald Trump’s violation of the U.S. Constitution’s Emoluments Clause made him impeachable on day one of his ill-gotten presidency, and every day since has brought him closer to removal from office over his ties to Russia, including a six-agency task force that is investigating possible collusion between Trump associates and the Russians; the use of his presidency to promote and profit from his Mar-a-Lago resort; the potential compromise of national security information at Mar-a-Lago; the resignation in disgrace of Trump’s National Security Advisor Michael Flynn; the cover-up of Flynn’s conduct by the Trump White House; the recusal of Trump Attorney General Jeff Sessions after lying to Congress; and finally, Trump’s potentially libelous lies about President Obama this past weekend.

In an appearance on MSNBC this weekend, Shareblue Executive Editor Jess McIntosh addressed the justified drumbeat for impeachment among the grassroots by explaining just what it is that elected Democrats should be doing in response:

RIVERA: What is that tightrope walk here that Democrats need to have, to get that balance between resisting the president, without overplaying it so that it backfires on them?

MCINTOSH: I think this is one of those instances, and we’re seeing it more and more since Trump took office, of the grassroots is actually outpacing Democrats in Washington. They are going farther than Democratic lawmakers are willing, or even able, to go. You can’t impeach when you are in the minority party. Right now, you see Democratic lawmakers, pretty much to a person, saying that we need a special prosecutor to look into Trump’s collusion with Russia. I think that seems to be the general sense. Everyone is behind that. Even some Republicans are behind that. But when you go to those town halls, people are terrified at what he has done in the few short weeks that he’s been in office, and they want to make it stop. They want to protect their communities, they want to protect their values, they want to see him out of office as quickly as possible.

So, I feel for the Democratic lawmakers who have to face folks who want them to impeach immediately, when of course that’s not something that they can do. But standing firm on a special prosecutor, I think, is exactly where they need to be now, and it’s where they are.

As McIntosh correctly notes, impeachment is a political process, and without a majority in the House of Representatives, Democrats have absolutely no control over Trump’s impeachment — let alone his removal by the Senate — no matter what he may be guilty of. Moving that ball will require two things.

The first is overwhelming public support, which is currently high but not quite in the majority. But to McIntosh’s point, public support specifically for a special prosecutor is overwhelming at 65 percent (including 43 percent of Republicans). A (very) few Republican lawmakers have already expressed support for such an investigation, and Republicans conspicuously abandoned Trump over the weekend when it came time to defend his lies against Obama. They are ripe to be swayed on this issue.

That makes possible the second requirement to move impeachment without a majority: Political cover in the form of overwhelming evidence. Much of the heat on Trump comes from leaked intelligence reports from agencies which are primarily designed to safeguard national security, not develop evidence of crimes. An independent commission and a special prosecutor will have the ability to develop the leads provided by intelligence agencies with subpoenas and sworn testimony.

With Vice President Mike Pence on deck, conservative Republicans have little incentive to preserve a Trump presidency at their own political expense, so the tipping point for evidence against Trump may be lower than anyone expects.

In the meantime, elected Democrats like Rep. Maxine Waters (D-CA) are giving voice to those in the resistance who want and need to see the Trump presidency come to end. An independent investigation by a special prosecutor is the necessary first step to that end.