From this sentence:
And given Trump's uneven attempts to unite the nation in the past, he would face a huge assignment in making a meaningful impact, not to mention his habit of undermining his own scripted addresses with follow-up tweets that reignite controversy.
What did the author mean by deeming Trumps' attempts uneven?
Oxford defines uneven as "not having the same quality in all parts".
If the definition above is the one which fits this context does that mean some of Trump's attempts lacked strength, insistence, firmness?