Britain has a hung parliament, which means that neither party really has enough members to make a majority. The Democratic Unionist Party (DUP) is now being seen as a coalition ally for the Tories. That goes to my Thoughts on US Third Parties since the DUP is a relic of the troubles and known to people like me who spent time in Ulster, but pretty much ignored.
Unless we are talking about Iris Robinson, who is sort of the Ulster version of Michele Bachmann, but much more amusing. Iris went down with something called Irisgate.  Michele Bachmann is only an embarrassment for people who come from Minnesota (Iris did her part to embarrass Ulster Unionists, but did it in a way that was funny ).
So, Most people know little about the DUP besides it being a political party founded by Ian Paisley which Iris Robinson once belonged to: if even that much. Of course, that pretty much sums up the DUP for those who don't know anything about it.
On the other hand, this is a party which pretty much would be like the religious/reality challenged right wing of the US Republican Party: Except they had nothing to do with Irish Republicans since they were Unionists (people who know Irish politics will get that comment).
Well, other than trying to kill the Irish Republicans (which clarifies the previous comment a bit).
Where was I? Oh, yeah, an otherwise insignificant party is playing a big role since there isn't a real majority in parliament, which also gets into how a parliamentary system works.
That is the party with a majority runs the show. The leader of the majority party runs the government. If the party can't run the government it is dissolved, which happens if they can't pass a budget bill.
Taking that description it is easy to see why the US isn't a parliamentary democracy since the current "leader" not only lost the election, but lost it with 46.4% of the popular vote (his opponent did slightly better with 48.5%, but still not a majority). The opposition is known to not pass budget bills, leading to the government actually shutting down.
The US would go through governments faster than the Italians or Belgians, making both countries seem paragons of stability, if it were a parliamentary democracy.
Seriously, the bottom line of watching the UK election is that the US has a defacto parliamentary system since the legislature has the power of the purse. Any small party (or faction) is better off being separate since the large "coalition" parties are meaningless.
Another thing I have to say is that people are sick of politics as usual. The Brexit vote, US, French, and UK elections have demonstrated that "non-traditional" politicians can do well. Bernie did a hell of a lot better than I thought he would have. And Trump showed that a clever politician can game the system (he spent far less than Clinton and got free publicity by being outrageous).
Also, people need to understand they are not as powerless as they are led to believe. In the US, they can vote their consciences in legislative elections to make more of a statement than they can in the presidential election. The real power is in the legislature (which makes the electoral college superfluous).
And the establishment parties need to understand that they are near the end of life if they don't undergo drastic changes.
 Irisgate probably made Iris Robinson better known than her husband, Peter, which compounded the embarrassment since Peter Robinson was DUP leader at the time.
 Alternate version of this here.