Things started trending that way when it became clear that while the Mueller Report showed no smoking gun on illegal collusion with Russia, it did show multiple smoking guns on obstruction of justice, or attempted obstruction of justice. Now that Trump is refusing to honor Congress’ lawful requests for information (including but not limited to Trump’s tax returns), there are even more grounds for impeachment being created.
More voices are now calling for impeachment, including an increasing number of voices on the center and (anti-Trump) right who were previously hesitant to do so. Interestingly, Bernie Sanders is (at the time of writing this) still hesitant. That’s because he fears it will be an exercise in futility that distracts the Democrats from being more than an anti-Trump party.
On the exercise in futility part, yes. It is all but certain that the GOP majority in the Senate will refuse to convict; to the loyal fascist, Il Duce can by definition do no wrong. On the distraction part, maybe. It should be possible for Democrats to walk and chew gum at the same time. But it’s a valid worry, since the Democrats do definitely need to be more than just the anti-Trump party.
I am compelled to reiterate (I mentioned it in passing above) that impeachment and conviction are two entirely different things, and odds do not favor conviction and removal from office by the Senate.