Will Kennedy retire and be Republicans' Senate savior?

"Kennedy is going to retire around sometime early summer," predicted GOP Sen. Dean Heller of Nevada, who is rated by CNN as one of the two most vulnerable Republican senators vying for reelection in November. Politico reported that it obtained audio of Heller speaking at an event in Las Vegas last week.

Heller continued, "Which I'm hoping will get our base a little motivated because right now they're not very motivated. But I think a new Supreme Court justice will get them motivated."

Sources close to Kennedy, who will turn 82 in July, told CNN last summer that he was seriously considering retirement, so a decision by him to step down would not come as a complete shock.

It is true that Republicans have a successful track record with Supreme Court nominations.

Senate Majority Leader Mitch McConnell used his power over the Senate floor to ice Merrick Garland, President Barack Obama's nominee to replace Justice Antonin Scalia after his February 2016 death, for nearly a year.

The ultimate nomination and confirmation of Neil Gorsuch to that seat, albeit after changing Senate rules, is the unqualified high mark of Trump's early months in office.

That guaranteed Republicans would have a very specific and important issue on which to vote. There's no doubt it helped Donald Trump defeat Hillary Clinton.

In exit polls, 21% of 2016 voters said the Supreme Court was their most important factor in their vote. Trump won those voters 56% to Clinton's 41%.

More generally, 70% of voters said the Supreme Court was an important issue. Trump won them more narrowly with 49%.

Heller is also right that it's an issue that resonates more with the base of GOP.

A CNN/ORC poll in October just before the 2016 election shows that the issue of the Supreme Court is more important to the conservatives that form the base of the GOP. Sixty-four percent of conservative Republicans said the Supreme Court was an "extremely important" issue in determining their vote. Just 41% of moderates, regardless of party, said the same. Fifty-eight percent of Trump supporters in that poll said it was extremely important compared to 46% of Clinton voters.

Of course, the issue is important to liberals as well. And since Kennedy is seen as the key swing vote on the issue of abortion, his retirement could just as easily have the consequence of motivating more supporters of abortion rights.

However, the map in 2018 favors Republicans. Heller is one of only two Republicans that CNN rates "tossup" compared to six Democrats. And Republicans are defending just eight seats. Democrats are defending 26.

Despite that advantage, the national mood seems to favor Democrats as Trump's approval rating remains historically low.

A Kennedy retirement would allow Trump to cement a conservative legacy on the court. Kennedy is often viewed as the current court's swing justice. His willingness to side with liberal justices has been crucial.

A Kennedy retirement would give Trump the chance to replace a relative centrist with a younger, and more conservative nominee, guaranteeing a staunch right-leaning block on the court that could last for decades. Kennedy's wiliness to side with liberal justices on issues such as affirmative action, abortion access access and same-sex marriage infuriated judicial conservatives and they'd relish the opportunity to replace him.

But, as CNN's Ariane de Vogue has written, Kennedy is likely to be aware that a retirement that close to an election is sure to further politicize his successor. Under normal circumstances, justices don't like to retire during an election year. That's why so many people thought that if Kennedy had any notion of retiring he would have done so last year to insulate the court from political firestorms. As things stand now, if he were to step down the hearings of his successor, as Heller pointed out, could well be a political firestorm. And if, there were no hearings this summer, and the Senate flipped it's even possible there could be an open seat for an extended period as the Senate battled it out.