What you saw was one convention of a party presently in power, and one convention of a party not in power.
A minority party has a couple of choices. You can go along with being a minority party, achieving small victories here and there, trying to force a compromise from the majority by offering "bipartisan" support in exchange for shaving the sharper edges off of the more unpopular legislation. This is how the general public would probably prefer that the party out of power act, and at various times in our history we've actually seen that occur. The problem, from the minority party standpoint is it can lead to a sense that the legislative branch is actually accomplishing something, and lead to perpetual minority status.
A second option for a minority party is to obstruct. You say the sun comes up in the east, I say it comes up in the west. Whatever you want, I don't want. Thwart the agenda of the executive branch at every turn. As a result, not a lot gets done (not necessarily a terrible outcome), or legislation gets rammed through and then the other party just does everything they can to badmouth it, obstruct it, overturn it, or at a minimum, run against it in the next election.
The Republicans have chosen option 2. Anyone who thinks they're the first and only party to have adopted this tactic is being a bit naive.
When a party takes that approach, politics takes on what looks like a particularily vicious tone, and it appears that one party is offering "solutions" and the other party is offering "attacks." But it's just politics, and that's why politics is a bunch of bs.
