The key Republican senators to watch in the tax bill showdown

Senate Republicans are planning a vote this week on a sweeping tax bill that would reduce taxes, particularly on corporations and the wealthy, by billions of dollars and repeal Obamacare’s individual mandate — and Majority Leader Mitch McConnell is getting closer to having enough votes to pass it.

The Senate leader has been using a flurry of last-minute dealmaking to win over holdout senators. And he’s making progress. Three senators who had previously expressed concerns — Sens. Lisa Murkowski (R-AK), Jerry Moran (R-KS) and James Lankford (R-OK) — have now said they’d support the bill.

There are still enough holdouts that the bill could potentially fail. Some senators are worried about the effects of the tax changes on their constituents, some have objected to how the business tax changes are handled, and some say they don’t want to increase the federal deficit.

Probably the most likely way the bill fails at this point is through “no” votes from at least three of these four senators: Susan Collins (R-ME), John McCain (R-AZ), Bob Corker (R-TN), and Jeff Flake (R-AZ).

Yet most of them have sounded optimistic about the bill in recent days. And the GOP is under enormous pressure from President Donald Trump and from their wealthy donors to pass the measure, to avert ending a year of full Republican control of Washington with no significant legislative accomplishments.

The Senate is set to begin voting on amendments to the tax bill on Wednesday, with a potential vote on final passage for later this week. Here, then, are the key GOP senators who need to be won over.

The retiring deficit hawks with nothing to lose: Bob Corker and Jeff Flake

Sen. Bob Corker of Tennessee and Sen. Jeff Flake of Arizona have a few things in common. Both are deficit hawks who have expressed concern that the GOP’s eagerness to cut taxes will lead them to blow up the federal deficit. Both have clashed repeatedly with President Trump this year. And both are retiring in 2018 — which gives their party’s leaders little leverage over them.

The current version of the Senate tax bill would add a little less than $1.5 trillion to the deficit over the next 10 years. But on paper, it would not add to the deficit in years after that — because many of its tax cuts are set to expire.

Here’s the problem: It’s obvious to everyone that Congress will be under enormous pressure not to let any of the bill’s tax cuts actually expire, but rather to extend them. That’s what’s tended to happen in similar situations in the past, and indeed, White House officials and some conservative Republican senators are openly saying that they hope it would happen again.

But if the bill’s tax cuts won’t actually expire as planned, then they’ll naturally keep on adding to the deficit, as Flake has pointed out. “The savings, the score, it just isn’t valid because you know that they’re not going to follow through,” he told Politico recently. “You can’t assume that we’ll grow a backbone later. If we can’t do it now, then it’s tough to do it later.”

Corker, meanwhile, has said repeatedly in recent months that he won’t support a tax bill that adds even “one penny to the deficit.” However, he has sometimes left a bit of wiggle room there. For instance, he’s suggested that he might accept “a reasonable score on dynamic growth,” meaning that he’s basically willing to assume the tax cuts will generate significant revenue by stimulating economic growth.

On Tuesday afternoon, though, Corker said he’d won a concession that the bill would include “a trigger to kick in additional revenues” if the tax bill expanded the deficit too much, and sounded positive on the effort. (The details here aren’t yet known.)

And on Wednesday, both Corker and Flake said they’d vote to begin debate on the tax bill before the full Senate. That doesn’t mean they’ll vote to support it in the end, but for now, they’re letting the process move forward.

The moderate: Susan Collins

Next, there’s the perennial tough vote for Republicans to lock down: Sens. Susan Collins (R-ME). She famously voted against the Senate’s Obamacare repeal bill earlier this year. And for now, at least, the Senate’s tax bill includes a major health care-related provision: the repeal of Obamacare’s individual mandate.

Collins has explicitly said she wants this dropped from the tax bill. “The fact is that if you do pull this piece of the Affordable Care Act out, for some middle-income families, the increased premium is going to cancel out the tax cut that they would get,” she said recently. She’s also criticized the bill’s cuts in the estate tax. But she told reporters Tuesday that she was optimistic that many of her concerns would be addressed:

The wild card: John McCain

Then, of course, there’s Sen. John McCain (R-AZ), who as of Monday night said he was undecided on the bill and concerned about “a lot of things” in it.

McCain has a history of defying his party — including on taxes. He voted against President George W. Bush’s tax cut bills in 2001 and 2003, and back in July, he was the decisive vote that tanked his party’s effort to repeal the Affordable Care Act. He’s currently battling cancer and won’t likely face another reelection in his career, meaning he has a lot of freedom to vote however he likes.

To explain his health vote, McCain complained mainly about the process and lack of bipartisanship — the health bill didn’t proceed through the committee process and through “regular order,” he said.

Now the tax bill has indeed proceeded through the Senate Finance Committee, and McCain released a statement praising that effort. The statement said he hoped that on the Senate floor, “both sides of the aisle” would have “sufficient opportunity to debate the merits of tax reform and offer amendments.”

So far, though, bipartisanship has been nowhere to be found. It remains to be seen, then, whether the tax reform process as a whole will meet with McCain’s approval — or whether he’ll pull off another maverick defection.

The pass-through-ers: Ron Johnson and Steve Daines

Finally, Sens. Ron Johnson (R-WI) and Steve Daines (R-MT) are worried that the tax bill doesn’t cut taxes enough for certain businesses.

Specifically, they’re worried about “pass-throughs” — businesses that aren’t subject to the corporate tax, but rather “pass through” their income to their owners, after which it’s taxed under individual tax rates. (Many pass-throughs are small businesses, but some — like the Trump Organization — are enormous.)

Johnson has been the most outspoken — he said earlier this month that he’d refuse to support the tax bill unless it did more to cut taxes for pass-throughs. Daines has reportedly made similar arguments in private.

Most political observers don’t think Johnson and Daines are particularly likely to oppose the bill in the end. It’s generally expected that they’ll come around after the bill is modified somehow to at least partly address their concerns. Still, for now, they remain holdouts.