The Democrats had bigger margins in both the House and Senate, and still had to compromise like hell (eliminating a public option, etc.) to barely squeak ObamaCare through the House and Senate. A major problem with the GOP coming together is that there are simply too many factions unwilling to do that.
Half the people in here are blaming Trump for not showing more "leadership" and getting the Senate bill through, while the other half are applauding Mike Lee for not supporting the Senate Bill. The reality is that even here on TBR, you have people with very different ideas of what is acceptable, and few willing to compromise. Why assume that the people we elect are any different?
The really sad part about this is that the only way to overcome it is to get more Republicans in Congress so that the margins aren't so thin, and we can afford to lose more than a couple votes. But now, you have people arguing that rather than try to send more conservatives Republicans to Congress, conservatives shouldn't vote for Republicans at all any more, but should instead vote third party.