I guess you'll have to read the proposed indictment to find out. I might expect emoluments, obstruction of justice (as per Nixon), and collusion with a hostile foreign power to be in the mix.
Even then it's basically dead until something else changes. At this point only 3% of Democrats were willing to sign on sponsoring impeachment. Nancy Pelosi is on record earlier this month saying she doesn't think impeachment is someplace the House should go based on the current evidence. Till most Democrats in the House support impeachment simply being a majority is not enough.
Political theater. It's the same reason Republicans passed numerous measures to overturn ACA for Obama to immediately veto. Appeal to the part of the base who doesn't care that it's pointless as long as action is being taken. It can also sort out internal caucus politics by highlighting issues in front of the electorate.
It's obvious that introducing impeachment bills makes the Trump dupes/dopes posting to this forum upset enough to post about it, so that makes it worthwhile to do.
The reasoning still applies. One was the party leadership itself scheduling the hopeless attempt to advance political interests. This is minority group of the Democratic caucus using the hopeless attempt for their smaller groups interests. The tool isn't particularly different just the size of the group using it.
