The internal conflicts that have roiled the Republican Party in the last nine years or so have been more about tactics than substance, no matter how intense they got. For instance, the Tea Partiers and "establishment" Republicans all wanted to repeal the Affordable Care Act, but the former thought it was worth shutting down the government over, while the latter thought that would be futile. Every once in a while there'd be an actual disagreement about policy goals, but most of the time they were arguing about how bold they should be and what political risks they should take to arrive at the place they all wanted to go.

Today, having succeeded in accomplishing their most important, deeply held, and universally agreed-upon goal — cutting taxes for corporations and the wealthy — Republicans face a fateful decision. Do they launch an all-out assault on our system of social supports, or hunker down and wait for the next election to be over?

There are two competing theories at work, and two Republican leaders with very different political approaches who will be competing to set the party's agenda.

Looming over this question is the 2018 midterm election, which is increasingly looking like it could be a disaster for the GOP. While they're hoping that the tax bill will become hugely popular and mitigate the damage, extensive polling and recent election results show they're in deep trouble. And they know it. As Politico recently reported, President Trump's political advisers "are bracing for a possible bloodbath in the 2018 midterms, which could obliterate the Republican congressional majorities and paralyze the president's legislative agenda."

If even one house of Congress falls to the Democrats, the big, sweeping changes Republicans would like to see will be impossible; all that's left will be executive actions and tweaks to regulations, which are neither comprehensive nor lasting enough to be truly satisfying. So one way to deal with that reality is to go full steam ahead. If we might lose our majorities a year from now, this first theory goes, let's pass everything we've ever wanted to do while we still have the chance.

That seems to be Speaker of the House Paul Ryan's perspective. As he told Stephen Hayes of the conservative Weekly Standard, he's eager to take a knife to the government's most cherished health-care and pension programs:

Ryan isn't one to bask in the glow of past accomplishments, and I ask him about his priorities for 2018. He names three: entitlement reform, welfare reform, and, surprisingly, health-care reform. "I don't think the health-care issue is done," he says, indicating a willingness to revisit ObamaCare as early as January … Ryan concedes that Trump is opposed to tackling the two entitlements that drive the national debt — Medicare and Social Security — but he's determined to press his case. "We're never going to give up on entitlement reform and the things we need to do to get the debt under control," Ryan says. [Weekly Standard]

So Democrats will scream that Republicans just passed a deficit-exploding $1.5 trillion tax cut and now have the nerve to say we must go after benefits for poor and middle-class people because of the debt? Who cares? Let 'em scream. We've got the majority and we're going to use it.

It's probably not an accident that Ryan is reportedly considering retiring after 2018; if he can make his twin dreams of cutting taxes and crippling the safety net a reality, there wouldn't be much more to do. That's because Ryan is above all an ideologue, motivated by firmly held beliefs about policy. His Senate counterpart Mitch McConnell, however, is not an ideologue at all. He's a realist, or if you prefer, a cynic.

For McConnell, politics is and has always been much more about seizing and holding power than about what you do with it once you've got it. And right now, with just a 51-49 margin in the Senate, 2018 is no doubt on his mind. His theory seems to be that with an electorate already considering tossing Republicans out of power, the best approach is not to make them any angrier than they already are.

Which is why he is dismissing the idea of an assault on the safety net. "I don't think, as a practical matter in the Senate, we can do entitlement reform without bipartisan agreement," McConnell told The Washington Post. "It applies to entitlements in general — Medicare, Social Security, welfare — they're so doubled down on that, I'm not going to devote floor time to something that has no Democratic support."

McConnell may blame the Democrats, but he knows well that an effort to cut Medicare, Medicaid, and Social Security would be a political disaster for the GOP, one that would make their 2018 problems even worse. As a matter of fact, there may be no single thing they could attempt that would be less popular. They already tried to go after what they assumed was the least beloved of those programs — Medicaid — and they learned that the American public loves it. That more than anything else is what killed their attempt to repeal the ACA.

Where does President Trump fit into all this? During the campaign, he often said that he didn't want to cut Medicare, Medicaid, or Social Security. But everyone understands that Trump has no real beliefs about any of it; he was perfectly happy to go along with an ACA repeal plan that would have eviscerated Medicaid.

He's open to persuasion, and some have figured out that they might win Trump's assent to go after any particular safety net program by calling it "welfare." Even though actual welfare is a dessicated husk of what it once was (it makes up about 0.004 percent of the federal budget), the words "welfare reform" have begun coming out of Republican mouths again for the first time in years, referring not just to welfare but to food stamps or any other program that helps poor people.

But when it comes to policy, Trump is nothing if not fickle, and any real effort at cutting the safety net will play out over an extended period of time, shining a spotlight on Republican heartlessness and reinforcing all the arguments Democrats are making as we head toward next November. In this kind of a situation, if one of the controlling parties thinks the best approach is to do nothing — as Mitch McConnell apparently does — that can grind the effort to a halt. Unless someone can persuade him otherwise, Paul Ryan's dream may have to wait.