Examples abound, but just as the candidates for the Democratic party's nomination for president are scrambling to outflank each other by proposing more and more giveaways and free stuff (including, but not limited to, health care, child care, day care, college, vacations, parental leave, abortion, guaranteed employment, no border walls - including the removal of the onesie already have), they also are outdoing each other on which Constitutional provision they would eliminate first. This reminds us of another Broadway song, "Anything You Can Do I Can Do Better."
The various candidates want to eliminate the Electoral College; recast the Senate to reflect population; modify the First Amendment, the Second Amendment, and various other parts of the Bill of Rights; and probably a lot more. All this because their chosen candidate didn't win in 2016.
We have nothing against reforming our system, although "keeping it up to date" is not our purpose. How about reforming the electoral college by dividing it according to congressional districts won, which already is done by Maine and Nebraska? That would more accurately reflect the popular will than the current "winner take all system'" which presently has the effect of disregarding Democrat votes in Texas or Republican ones in California or New York; and yet would retain the individuality of each state. It would be a lot easier to steal an election in a purely popular vote system or a winner take all system than in a proportionate system. Wise reform is desirable; changing the rules because one lost is selfish and petty and often short-sighted.
The progressives also don't like it that Wyoming and Alaska have the same number of senators as California, so they want to do away with the senate as representing the various states, and allot it by population instead. They don't like the Second Amendment, which guarantees the right to bear arms, and they want to modify the First Amendment, because they don't think that people who refuse to accept their theories of "climate change" or who might disagree with the leftist political philosophy should have the right to express those opinions. They don't care that the underpinnings of our system, the reasons that those thirteen colonies of different sizes and populations united and formed a "more perfect union" was because of the composition of the senate, the electoral college, and the Bill of Rights, the very things they are attacking today. If you don't believe it, look it up.
Several of the Founding Fathers made remarks along the lines of "forming this system of government is hard enough, but keeping it will be even harder." They were correct, and America fought a Civil War over slavery and the right to secede, because the voices of compromise or practical common sense did not prevail. Our nation has survived and thrived and prospered thanks to our form of government, which set about to protect the inalienable and God-given rights of the people, and did so in ways that protected minorities, encouraged national rather than regional candidates, and retained the identities of each state, even the small ones, as it simultaneously empowered the more populous ones. It also devised a system that accepts growth and improvement and change. The progressives probably could tear that all down with relative ease, but could they ever build something that was as strong or has lasted as long?