There is nothing conservative about providing tax cuts, primarily to the wealthiest Americans, and dramatically increasing spending. Which is exactly what has happened, and generally all that was significant that happened, on each occasion Repubs had control over the past 35 years. In spite of the talk of the cuts increasing revenue, it was debatable the increases had anything to do with the cuts, and the increases never came close to catching up with spending, in effect the experience was one of increasing deficit. This started with Reagan, as documented by his economic advisors in a book they wrote after the presidency. That was in the days when conservative politicians actually cared about things like deficit spending, budgets, etc. How they care, but only as for the talking points to beat Democrats over the head with. Just look at a chart of deficit spending and you will see the greatest increases in Repubs have control. As a recent example, look at Trumps first two years. The Repubs had even greater majorities than the Dems do now, and they cut taxes and increased spending. I fear you're getting caught up in the words and politics. Repubs love to beat up Dems for spending, but in the last 40 years the generally the only spending Repubs fight is that for Americans. If the spending is for global corporations they are all in favor of it. If the tax cuts are for global corporations they are all over it. If the cuts are for Americans, such as payroll, etc, they fight them.

Favoring large corporations is not a Republican thing. Dems do it too. The difference is, as always, the Repubs are ahead of the Dems and are generally not attempting to help Americans. The Dems are still doing little things to placate Americans. The Repubs just do that not in actions but words. Both kowtowing to global corporations is systemic, in that the way our government operates causes that focus. Focus on global corporations due to their wealthiest owners and execs, industry groups, and lobbyists providing the bulk of money to politicians and their parties.

In a nutshell, neither party well represents Americans or even America, due to the system. One can't really win a federal seat if they spurn corporations, many of which are financially larger than most countries. The best recent evidence of this broken system is American picking alternative candidates: Trump, and while he didn't make it, Sanders. The odd thing is that average Americans of both parties are unhappy and seeking alternatives. And they are generally unhappy for the same reason, financially we're in a time when this generation is not doing as well as the previous. This is clear in the US's fall in standard of living relative to other countries, and fall in percentage of the global economy. The US has been in decline for at least 4 decades. And Americans are feeling the pinch, if not knowing why. The parties are taking advantage of the stress by suggesting the problem: immigration (when many more jobs were lost to automation, which is not discussed), over taxation, when pretty much all other countries have higher taxation, but that is changing. And distracting people from the corporate largess.

Why do Americans, who used to have some of the best prices in the world for most all products and services, now spend more than most citizens of other developed countries. Simple, the government supports it, as it is good for corporations. Rather than fostering competition and lower prices the government subsidizes outrageous pricing. This is no more evident in healthcare. And now Dems are making motions at fixing it, but even they are really not doing anything significant, they can't afford to lose the campaign and PAC money the healthcare industries contribute (insurance, Rx, hospitals, etc, etc). The Republicans don't even try, they talk about nonsensical things like cross state boarder competition for health insurance, when most of the insurance companies are in most all states. The real reason Republicans want this is at the behest of insurance companies who do not want to deal with individual states regulations - insurance regulation state controlled and pain for companies to deal with each state individually. I could go on and on, but I have already been too long.
No campaign finance reform, no joy.