Donald Trump is the GOP Presidential frontrunner but many Republican Senators, especially those who are up for re-election this year, are hesitant to support him.

His candidacy puts them in quite the conundrum. Do they officially endorse Trump and his divisive rhetoric that the voters appear to favor? Or do they go against the Republican party, voters, a likely Donald Trump candidacy and risk losing some of their supporters as well as their seat?

Pennsylvania’s own junior Senator Patrick Toomey is probably asking himself these exact questions. Toomey has not made any public announcements in favor or against a Donald Trump candidacy although prognosticators see it having a large impact on his re-election odds.

The closest he has come is the vague statement that “I will be supporting the Republican nominee, whoever that is.”

According to a the latest Harper Poll, Toomey is leading all his potential Democratic opponents, but is still under the important 50% threshold for incumbents.

A recent Washington Post article found that 29 of 54 of the Republican Senators have “indicated” they will support whoever the nominee is, even if it is Donald Trump. Alabama Sen. Jeff Sessions is still the only Republican Senator, however, who’s actually come out and officially endorse Trump for President.

On the other hand, only Sen. Ben Sasse of Nebraska, has come out against Donald Trump stating that “conservatives will need to find a third option” if Donald Trump were to win the Republican nomination.

How Pat Toomey will handle Donald Trump will be one of the most intriguing subplots of the 2016 election.