Try this on for size, sure to iritate many.

For most of the 20th century most Americans knew, more or less, what their two parties stood for.
Today, America’s parties are more fragmented than usual. The Republicans are obviously fractured.  And the contradictions among Democrats, though less obvious, also run deep.

Donald Trump’s run for the presidency has prospered despite lacking all the things parties usually provide for a front-runner, strategists,  policies, money.  What is beyond strange is the failure to address the mismatch between grassroots supporters and the policy agenda into which Mr Trump has tapped so effectively. In its subsequent disarray, the party has simply failed the party members.  Hi-jacked by a minority group.  The rest of the party pretty much hates Trump and so others have joined the fray.  All unwilling to step aside because of their ego's and unite against Trump to bring a viable candidate that could win an election.  

Should Trump not win the nomination, his supporters will not support another candidate but will pout and stay home.  Should Trump be the candidate, some may support him, some may go the libertarian route however many will just stay home ensuring a Democrat either one would be elected.

For the Democrats,  the primaries have also revealed a powerful urge among activists to move the party leftward.  Bernie is the candidate of choice with Clinton morphing left to meet the challenge.  The primaries has also made it clear that Democrats are divided along generational lines. Bernie Sanders has thrashed Mrs Clinton in every contest among voters whose formative political experiences were the Iraq war (which she supported) and the financial crisis (blamed on her Wall Street supporters).   Older Democrats remember the party’s move to the center in the 1990s as pragmatic, correct and fruitful; younger ones consider it a betrayal.

Democrats were once the small-government party, opposing those who wanted a more powerful federal government and defending the interests of white southerners against Washington, now they are famous as the big-government party, pushing federal anti-poverty programs in the 20th century and government involvement in health care in the 21st.  Which are failures.  The Democrats have decided nut to trust the people and have instituted a policy of super delegates to ensure the party remains in control.  Should the vote in delegates be close, with the left fringe be angry at the betrayal by the super delegates?

All in all the fringe groups are ecstatic as they push their candidates and the results are likely to be disastrous for a broken country who can no longer understand the words from JFK's speech:

And so, my fellow Americans: ask not what your country can do for you - ask what you can do for your country. 

We no longer put forth the best and the brightest to do what's best for the country but the people who will give us what we want.