The late conservative columnist Robert Novak once quipped: “God put the Republican Party on Earth to cut taxes.” But tax reform is shaping up to be as difficult — or nearly as difficult — as repealing Obamacare.

The rest of this year and probably the early part of 2018 will be dominated by a drive to lower income taxes, reduce the number of tax brackets, slash corporate taxes, and simplify the tax code.

[lz_ndn video=33150473]

As with the failed Obamacare repeal effort, Republicans plan to avoid a Democratic filibuster by tying the tax cuts to the budget. The Senate GOP cleared that first initial hurdle last week by adopting a budget resolution.

But as with Obamacare, passing the budget is no guarantee that actual tax law will pass. If Republicans cannot woo any Senate Democrats, they will not be able to lose more than two senators from their own caucus.

Holding the fractious conference together is by no means assured. Here are the six Republicans most like to break ranks, from least to most likely:

6.) Roy Moore (R-Ala.). Moore is not even in the Senate yet. After taking out appointed Sen. Luther Strange (R-Ala.) in a special election primary, he still must get past Democrat Doug Jones in December. If Moore loses — and polls suggest it is a possibility — it almost certainly will cost the GOP majority a vote on the tax plan.

If Moore wins, he probably will vote for the measure. But he makes this list because the longtime state court judge has a blank legislative slate, because of his populist streak, and because his hostility toward Senate Majority Leader Mitch McConnell (R-Ky.) makes him a wild card.

If the final legislation includes compromises designed to woo moderates, Moore cannot be counted on as an automatic “yes” vote.

5.) Sen. Lisa Murkowski (R-Alaska). Murkowski is a Senate moderate and a perpetual annoyance to movement conservatives. After losing a Senate primary in 2010 to a conservative Tea Party candidate, she came back to win the general election as a write-in candidate.

Who do you think would win the Presidency?

By completing the poll, you agree to receive emails from LifeZette, occasional offers from our partners and that you've read and agree to our privacy policy and legal statement.

Murkowski was also one of three Republican senators who killed repeal of the Affordable Care Act — even though she’d voted to gut it in 2015.

Given that record, she cannot be counted on. But prospects for tax reform are better. She voted for the budget resolution, which allows for the possibility of opening the Arctic National Wildlife Refuge to oil drilling — long a priority for Murkowski and other Alaska politicians.

4.) Sen. Susan Collins (R-Maine). Like Murkowski, Collins helped kill repeal of Obamacare and has been one of the least reliable GOP votes in the Senate.

She approached the budget vote with her characteristic cautiousness, qualifying her support beforehand by declaring herself as a “likely yes” vote before casting a vote in favor. Earlier this month, she referred to the tax plan as “still a work in progress,” according to Bloomberg.

Collins also has voted against past attempts to repeal the estate tax, which is included in the current plan. On Thursday, she opposed an amendment by Sen. Bernie Sanders (I-Vt.) to exempt the top 1 percent from tax cuts but told reporters she would have supported an amendment with a lower income threshold.

In addition, Maine benefits more than most states from a tax provision that lets people deduct state and local taxes from their federal income taxes. Republican leaders have proposed eliminating that tax break as part of the reform plan.

However, Collins voted for tax cuts under George W. Bush in 2001 and 2003 and later voted to extend them.

3.) Sen. Rand Paul (R-Ky.). The libertarian-leaning Paul always has been an iconoclast among his Republican colleagues. He has a good relationship with President Donald Trump and agreed to vote in favor of starting debate on the budget last week. But he has demonstrated again and again that he is unafraid to buck the GOP leadership, even if it means casting lonely “no” votes. He did so again by voting against the budget.

Just because he opposed the budget — because it did not restrain spending enough — does not necessarily mean that he will oppose the ultimate tax legislation. But he is a good bet to vote “no” if he thinks it would irresponsibly increase the national debt, fail to rein in spending, or is flawed in some other way.

“I will fight for the biggest, boldest tax cut we can pass, but I could not in good conscience vote for a budget that ignores spending caps that have been the law of the land for years and simply pretend it didn’t matter,” he said in a statement. “We can be for lower taxes and spending restraint.”

Paul also has vowed not to support any measure that would increase taxes on anyone. That is a potential problem considering that independent analysts have projected that some upper-middle-class taxpayers would pay higher taxes as a result of losing deductions they currently enjoy.

“What I will not accept is a tax hike on the middle and upper middle class, sacrificing their paychecks on the altar of ‘reform,'” he wrote in Forbes earlier this month.

2.) Sen. Bob Corker (R-Tenn.). The retiring Tennessee senator no longer has to worry about voters and has been engaged in a feud with Trump. That is a bad combination for Republicans hoping for party unity on tax reform.

Corker also voted for the budget but called it the “biggest hoax cast upon the American people ever.”

Corker said “there is no way in hell I’m voting for” tax cuts that add even “one penny” to the deficit. If he holds to that, he’ll be a “no” vote, since it is unlikely the Congressional Budget Office or outside scorekeepers will project the economy will grow fast enough to entirely overcome lost revenue from the tax cuts.

1.) Sen. John McCain (R-Ariz.). McCain, long a thorn in Trump’s side, has to be considered an even more likely “no” vote than Paul or Corker.

In addition to his testy relationship with Trump and helping to stop the repeal of Obamacare, the maverick senator has a history of opposing tax cuts. In 2001, he was one of just two Republican senators to vote against Bush’s first tax cut. He also voted against a second round of tax cuts in 2003.

[lz_related_box id=”854677″]

What’s more, McCain explained after the budget vote that he was willing to support it, even though it does not spend as much on defense as he would like, because that extra funding can materialize when Congress writes its spending bills — regardless of what the budget says.

He told Bloomberg last month that he wants bipartisan agreement on tax cuts, an ominous sign, given that this is the justification he gave for killing the Obamacare repeal — despite the fact that he also voted for a budget resolution that would have allowed it with a simple majority.

“We need to do it in a bipartisan fashion,” McCain said. “I am committed, as I’ve said before, to a bipartisan approach, such as we’ve been doing in the Armed Services Committee for the last 53 years.”

(photo credit, homepage image: Donald Trump, cut out, CC BY-SA 2.0, by Gage Skidmore; photo credit, article image: Donald Trump at Aston, PA…,cut out and colored, CC BY 2.0, by Michael Vadon / John McCain, cut out and colored,  CC BY-SA 2.0, by Gage Skidmore / Rand Paul, cut out and colored, CC BY-SA 2.0, by Gage Skidmore)