Meaning of "tentative" in a context

Hello everyone

I have a question about the meaning of the verb "tentative". So in my grammar book there's an article about modals could, may, might that are used to express possibility. And there's a section where it says:

The use of these modals in the press seems to suggest may and might as tentative, with could expressing a stronger possibility, as shown in these extracts from The Guardian:

The change in Britain's ethnic make-up may already be enough to cost (the Government) the next election.

The ethnic minority vote could be a key factor in the next elections.

So does "tentative" mean "less certain"/"less definite" in this context?

Thank you beforehand for your answers

P.S. Here's a screenshot of this section in case something will be unclear for you.

P.P.S. Just wanted to make sure I understand the verb "suggest" right, does "suggest" in this context mean "indicate/show"?