No, a Republican congress would not change things. A truly conservative constitutionally-minded congress, however would. Unfortunately, you cannot define most of the Republicans in office as either conservative or constitutionally-minded.
The term "constitutional" has been used so much in attempts to frame a "well duh" argument that it has been trivialized beyond all significance. Which version of constitution are you talking about and which founders interpretation of it? The post 10th amendment version, the post 14th amendment version, the post 16th and 17th amendment version? Each of those versions have placed more and more day to day power into the 'constitutional" powers of the Federal government. I am really sick of the term "constitutional" being bandied about as if it settled all arguments and no debate is possible.
That's very true.
But real conservatives are very patient folks. In fact, that's what conservatism is all about. We prefer gradual development to abrupt change. Conservative incrementalism, works well in politics, because political change is a slow process. Things don't happen overnight. Seven decades of Democrats building on creeping policies of liberal socialism, has proven that. If you want abrupt change, thats called a revolution.