The Trump tax plan was so rushed we can't even assess its impact yet

(CNN)Stan Collender has been explaining taxes and budgets to me for the better part of the last decade. Stan spent time on the House and Senate Budget Committees and wrote a book titled: "The Guide to the Federal Budget." Heck, his Twitter handle is @thebudgetguy! So when House Republicans -- finally -- unveiled their tax proposal on Thursday, I reached out to Stan to answer some questions and make some predictions. Our conversations -- conducted via email and lightly edited for flow -- is below.

Cillizza: Tax plans are always SUPER complicated. Boil this one down. What are the three-to-five big changes it would make to our current tax code?
Collender: The tax bill announced today almost certainly will not be what ultimately is enacted (that is, if anything is enacted), but the top provisions are: the reduction in the top corporate income tax rate; the changes in the pass-through rate for businesses and the increase in the standard deduction that will wreak havoc with many of the most popular tax breaks for individuals especially mortgage interest, state and local taxation, charitable giving and student loan interest.
What makes these the most important changes is that they all create big losers as well as winners. No doubt that's why House Republicans are racing to vote on the bill so quickly. If a legitimate and appropriate debate on this proposal were allowed, massive opposition would develop as voters realize they may be giving up more than they're getting.
    FYI ... even minor legislative proposals typically get more consideration and are debated longer than this tax bill, and this is anything but a minor bill.
    Cillizza: Democrats say this is a plan that overwhelmingly will benefit millionaires and billionaires. Trump and the rest of the GOP say it will primarily benefit the middle class. Who's wrong?
    Collender: This tax bill was done so last-minute that we don't yet have what tax geeks call "distribution tables," that answer this question with some statistical precision. The proponents of a tax bill typically have those tables in hand when it's released so there some substantive "oomph" behind their politically motivated assertions. The fact that they didn't have them today tells you both that this bill came together at the very last minute and that you shouldn't take the Republican claims that this primarily benefits the middle class at face value. If it did, we would already have statistics to prove it.
    Cillizza: This tax plan adds to the deficit. Bigly. How different is this proposal than, say, the George W. Bush tax cut package of 2001?
    Collender: The George W. tax cut was based on the (completely inaccurate) projection that there would be a multi-trillion dollar budget surplus in the coming years that could and should be used to cut taxes. The current tax cut bill doesn't give a damn about the fact that we already have a huge annual budget deficit that will get much bigger (I estimate by another $200 billion a year) if this passes. So much for Republicans being fiscally righteous when it comes to the deficit and national debt.
    Cillizza: Trump keeps saying this is a tax plan that vulnerable Democrats -- there are 10 Democratic Senators up in 2018 in states Trump won -- need to support this tax bill. What's the likelihood more than one votes for the final product? Why?
    Collender: Donald Trump is the last person House and Senate Democrats are going to take political advice from on this bill, especially because in many ways it's a dagger pointed directly at their districts and states and key constituencies. Besides, Trump really needs to be far more worried about Republicans than Democrats; they're the ones that will cause this bill to pass or fail.
    With Trump's approval rating at 33% in the most recent Gallup poll, opposing him won't be hard at all for any Democrat. Many will do it gleefully.
    Cillizza: Finish this sentence: "The Trump tax plan passes Congress by _________ [date]." Now, explain.
    Collender: "The Trump tax plan passes Congress by June 30, 2018 ... or it will never pass at all."
    In light of everything that's happened in the past 24 hours, does anyone really think this will be a slam dunk?