It’s approaching that part of the campaign where the candidates begin to name who is on their short list to be added to the ticket as their Vice Presidential running mate.

Ted Cruz has been quiet about his choices, but the media reports his campaign has begun to shift resources to the selection process.

Donald Trump, on the other hand, name-checked three Republicans and the political world was buzzing.

In an interview with USA Today, Trump listed Florida Senator Marco Rubio, Ohio Governor John Kasich and Wisconsin Governor Scott Walker as his top contenders:

“Yes, I like Marco Rubio. Yeah, I could,” he answered. As for a potential Rubio Vice President: “There are people I have in mind in terms of Vice President. I just haven’t told anybody names. … I do like Marco. I do like (John) Kasich … I like (Scott) Walker actually in a lot of ways. I hit him very hard. … But I’ve always liked him. There are people I like, but I don’t think they like me because I have hit them hard.”

All three represent states that are in play in the general election.

No Republican has ever won the White House without winning Ohio, and John Kasich has astronomical in-state approval numbers and also bested Trump in their primary contest.

Rubio’s home state of Florida was famously decisive in the 2000 election, and Barack Obama carried the state in both of his campaigns.

A selection of Rubio would also be an olive branch to the wings of the party still suspicious of Trump, both ideologically and practically.

As a Republican governor of a blue state with a lengthy record of conservative accomplishments, Scott Walker also reinforces Trump’s message of a get-things-done executive who can win industrial states.

In fact, many believe Trump’s path to the nomination centers on the industrial Midwest.

But that region has so far been unkind to Trump in the primaries.

While he won in Illinois and Michigan, Trump was thumped by Ted Cruz in Iowa and Wisconsin.

And many forecasters favor Cruz to emerge victorious in the May 3rd Indiana primary.

Selecting Walker or Kasich could not only add a state to the Republican column, but could shore up states where Trump badly needs to do well — in a region where he has underperformed in the primaries.

Before any candidate can compete in a general election, they must first win the primary.

And Trump appears to be heading into the Republican convention with the delegate lead, but still just short of the 1,237 necessary to win the nomination.

So it is no surprise that two of three Vice Presidential contenders control a large enough number of delegates to deliver Trump the nomination.

Rubio controls 171 delegates.

Kasich owns 143.

Scott Walker is a popular figure among the party regulars who will attend the convention as a delegate.

Name-checking all three is a signal to delegates favorable to those candidates that, if they support Trump, their man will be on the ticket.

All represent key states, constituencies and delegate blocks Donald Trump must appeal to if he is to win the Republican nomination.

Who do you favor as the Vice Presidential selection for the Republicans in 2016? Let us know in the comment section.