Donald Trump visited Missouri this week to deliver a thinly disguised campaign speech in which he tried to sell a tax cut for rich folks and corporations as “reform” that would benefit the middle-classes. And he did it in the middle of a major national disaster, yet. But hey, we already knew we weren’t dealing with a class act here.

But that’s not all Trump did in Missouri. He dumped a truckload of the patented Trump slime on Missouri’s Democratic senator, Claire McCaskill – which, incidentally, may have oversteped the legal line between thinly disguised campaigning and the straight-out real thing:

Speaking at an industrial-fan factory in Springfield, Trump singled out McCaskill, a Democrat who is up for reelection next year in a state the president won decisively in 2016.

“We must — we have no choice — we must lower our taxes. And your senator, Claire McCaskill, she must do this for you, and if she doesn’t do it for you, you have to vote her out of office,” Trump said to loud applause and whistling from the audience. “She’s got to make that commitment. She’s got to make that commitment. If she doesn’t do it — we just can’t do this anymore with the obstruction and the obstructionists.”

Ethics experts said the main issue raised by the president’s comments is whether he was ad-libbing or whether White House aides planned for him to urge McCaskill’s defeat..

In case you’re in doubt about whether or not Trump’s partisan jibes overstepped the line, bear in mind that taxpayers paid for him to come here and dishonestly take out after a senator from the opposite party, a senator moreover who’s made it clear that she’s willing and eager to participate in a discussion of real tax reform, as long as it’s really a cooperative process, rather than simply an invitation to mindlessly rubber stamp proposals that reflect the desires of those rich folks who serve to profit most.

What should McCaskill do in response to this unprovoked attack from the Republican’s president? It’s not always effective to respond to slime with a shovel – especially when the slime machine’s so hyperactive. But it occurs to me that there’s an available and potentially effective “shovel” that might fit right into McCaskill’s persona as a lawmaker who always watches out for her constituents’ fiscal interests.

Ask yourself who, off the top of your head, really needs to have his fiscal shenanigans spotlighted right now? If you said Donald Trump, give yourself an “A.”

Trump, among other abuses, has beggared the Secret Service with his regular $3 million weekend retreats to his own luxury hotels. And a big part of that $3 million in taxpayer cash flows straight into Trump’s own pocket since he’s declined to comp the Secret Service accommodations in return for the free protection he and his family receives. Wouldn’t that be the least that a man who claims to be a billionaire could do if he really has to spend almost every weekend at his own properties? And I may add that he takes these golfing weekends away in spite of the fine, big, white house the taxpayers have loaned him, a house where nobody has to pay extra for his protection.

If this isn’t an abuse that needs to checked, I don’t know what is.

What’s more, some intrepid lawmakers agree and are on the ball. Rep. Adam Schiff (D-CA) has introduced an amendment to the 2018 spending bill that would prohibit allocations to the Secret Service from being used to ” purchase, rent, or otherwise acquire goods or services, including hotel rooms, office space, or golf carts, from entities that are owned or operated by the President or the immediate family of the President.” And Schiff isn’t the only member of the House who’s appalled by Trump’s cavalier appropriation of federal money for himself: Rep. Steven Cohen (D-Tenn.) introduced sixteen appropriations amendments that would “prohibit federal spending at Trump-owned hotels, resorts and other Trump-owned businesses.” No more tax-money going to further enrich America’s wealthiest and – incidentally? -most corrupt President.

Seems to me that this and other fiscal abuses by the president – of which there are many – might be an excellent focus for hearings in the Senate, not to mention a profitable way for our fiscally-excited Senator McCaskill to deploy her energies. At the very least, she could start lending her vocal support to the House’s efforts to rein in Trump’s corruption. After all, nobody can work that fiscal shovel like Claire McCaskill.

Of course, as constitutional law professor Jacob Weisberg observed in a Slate interview, the best way to deal with presidential corruption is impeachment. Although impeachment has to originate in the House, McCaskill might profit from keeping the possibility in mind. Even though she’s tried to make it clear to pinkish citizens of red state Missouri that she doesn’t intend to “fight” the president, the time might come when fighting for Missourians means doing just that. And, of course, he’s already thrown the first punch; it might be time to see what kind of counter-punches our Senator is capable of delivering.