Independents now outnumber both major political parties, but they are evenly divided between the left and right. This might suggest that a centrist party would be successful, but I'm afraid the division between left and right independents is quite extreme with both sides positioned well outside the two existing parties.

Republicans have done a much better job at reaching out to right leaning independents than Dems have for the left because the Democratic party shares more with traditional Republicans than it does with more left leaning independents. This has caused the number of non-voting citizens to be largely the far left who favor more socialism and worker protections.

As the Republican party became more extreme in its attempt to capture the far right libertarian voters, it left room for the Democratic party to capture more centrist voters by simply moving to the right in favoring corporations and markets over the working class it used to represent until the fall of the New Deal and the advent of neoliberalism.

This has left anyone to the left of Eisenhower or Nixon without representation and the Republican party resembling many fascist regimes in history. It takes considerably more than the potential to win elections to move the Democratic party to the left. Its representatives are sharing in the glut of donations available from corporate and well heeled private interests that used to be the baliwick of Republicans.

It is better for those representatives to lose elections than to cave to the demands the far left makes, as there are always jobs waiting for them should they lose. Good luck breaking this dynamic at the polls or shaming Democrats into actually representing their voters. Such would require the threat of an outright armed rebellion, but the far right has bought up all of the guns and ammunition.