SPRINGFIELD — The buzz about Sen. Dick Durbin mulling a run to challenge Gov. Bruce Rauner echoed Wednesday throughout a rally full of Republicans.

First, it came in a laugh from Rauner, then a jab from a downstate congressman. Soon after, came an email blast from Durbin urging constituents to sign a petition to express “disappointment” in a recent Rauner veto.

Sure sounds like Durbin is gearing up for a run for governor.

The Springfield Democrat’s name has been swirling around for months as a potential challenger to Rauner in the 2018 election. But the veteran lawmaker hasn’t confirmed he’ll run, only saying he’ll make a decision after the November election.

Just before Rauner kicked off a Governor’s Day rally at the Illinois State Fair, Rauner laughed when asked about Durbin as a potential challenger, but grouped him into a category of “career politicians.”

“Illinois is broken. The career politicians that have been in power who believe in the same broken machine and are part of a same broken machine will never fix our problems,” Rauner said. “We need to transform our state — term limits, fair maps, job creating reforms, funding our schools properly — fundamentally we’ve got to transform the system.”

But U.S. Rep. Rodney Davis, R-Ill., was a little more literal in his thoughts on Durbin.

“How can a guy who got elected to go to Washington when I was 12 and in 5th grade, who’s watched this country’s debt explode to $19 trillion, think that he can fix the problems here in Springfield?” Davis asked the crowd at the Governor’s Day rally.

“Anybody think that could happen?” Davis asked, with the crowd chanting “No.’ “Are we going to elect Bruce Rauner again?” was answered with “yes” chants.

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Shortly after his name was called at the State Fair, Durbin sent out an email blast denouncing Rauner’s Friday veto of an automatic voter registration bill.

“We should be making it easier for people in this country to vote. I honestly don’t think this is a radical idea, which is why I was disappointed to see Illinois Governor Bruce Rauner veto legislation to modernize voter registration,” Durbin wrote.

In the email, Durbin asks constituents to sign a petition to express “disappointment” with Rauner’s action: “Tell Governor Rauner that it is unacceptable to veto modernizing voter registration in the state of Illinois by adding your name today.”

Durbin says in the email that he hopes the General Assembly overrides the governor’s veto.

“In the meantime, let’s make sure that Governor Rauner hears from people like us. He needs to know that we’re all going to continue to fight to make it easier for people in this country to vote,” Durbin wrote.

Durbin used much of his speech at an Illinois delegation breakfast last month at the Democratic National Convention to criticize Rauner over what he called attempts to divide the state.

“We cannot allow any politician to divide this state,” Durbin told Illinois Democrats.

Later, Durbin told reporters: “Any governor of Illinois who tries to divide this state, southern Illinois versus Chicago, one section against the other, does a disservice to the people he represents. We are one state.”